SELECT 
  cscart_products.product_id, 
  cscart_products.company_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = 'M', 
      CONCAT(
        cscart_products_categories.category_id, 
        'M'
      ), 
      cscart_products_categories.category_id
    )
  ) as category_ids, 
  cscart_products.product_code, 
  cscart_products.weight, 
  cscart_products.tracking, 
  cscart_product_descriptions.product, 
  cscart_product_descriptions.short_description, 
  cscart_products.is_edp, 
  cscart_products.edp_shipping, 
  cscart_products.shipping_freight, 
  cscart_products.free_shipping, 
  cscart_products.zero_price_action, 
  cscart_products.tax_ids, 
  cscart_products.qty_step, 
  cscart_products.list_qty_count, 
  cscart_products.max_qty, 
  cscart_products.min_qty, 
  cscart_products.amount as in_stock, 
  cscart_products.shipping_params, 
  cscart_companies.status as company_status, 
  cscart_products.out_of_stock_actions, 
  cscart_products.updated_timestamp, 
  cscart_company_descriptions.i18n_company as company_name 
FROM 
  cscart_products 
  LEFT JOIN cscart_product_descriptions ON cscart_product_descriptions.product_id = cscart_products.product_id 
  AND cscart_product_descriptions.lang_code = 'en' 
  INNER JOIN cscart_products_categories ON cscart_products_categories.product_id = cscart_products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND (
    cscart_products.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_products.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_products.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_products.status IN ('A', 'H') 
  LEFT JOIN cscart_companies ON cscart_companies.company_id = cscart_products.company_id 
  LEFT JOIN cscart_company_descriptions ON cscart_company_descriptions.company_id = cscart_products.company_id 
  AND cscart_company_descriptions.lang_code = 'en' 
WHERE 
  cscart_products.product_id = 339723 
GROUP BY 
  cscart_products.product_id

Query time 0.00088

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.40"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products",
            "access_type": "const",
            "possible_keys": [
              "PRIMARY",
              "status"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.00",
              "eval_cost": "0.20",
              "prefix_cost": "0.00",
              "data_read_per_join": "7K"
            },
            "used_columns": [
              "product_id",
              "product_code",
              "status",
              "company_id",
              "amount",
              "weight",
              "shipping_freight",
              "updated_timestamp",
              "usergroup_ids",
              "is_edp",
              "edp_shipping",
              "tracking",
              "free_shipping",
              "zero_price_action",
              "out_of_stock_actions",
              "min_qty",
              "max_qty",
              "qty_step",
              "list_qty_count",
              "tax_ids",
              "shipping_params"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_descriptions",
            "access_type": "const",
            "possible_keys": [
              "PRIMARY",
              "product_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "product_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "const",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.00",
              "eval_cost": "0.20",
              "prefix_cost": "0.00",
              "data_read_per_join": "6K"
            },
            "used_columns": [
              "product_id",
              "lang_code",
              "product",
              "short_description"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_companies",
            "access_type": "const",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "company_id"
            ],
            "key_length": "4",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.00",
              "eval_cost": "0.20",
              "prefix_cost": "0.00",
              "data_read_per_join": "9K"
            },
            "used_columns": [
              "company_id",
              "status"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_company_descriptions",
            "access_type": "const",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "company_id",
              "lang_code"
            ],
            "key_length": "10",
            "ref": [
              "const",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "0.00",
              "eval_cost": "0.20",
              "prefix_cost": "0.00",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "company_id",
              "lang_code",
              "i18n_company"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "1.00",
              "eval_cost": "0.20",
              "prefix_cost": "1.20",
              "data_read_per_join": "16"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "webmarco.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 0,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "1.00",
              "eval_cost": "0.01",
              "prefix_cost": "2.40",
              "data_read_per_join": "303"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`webmarco`.`cscart_categories`.`storefront_id` in (0,1)) and ((`webmarco`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`webmarco`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`webmarco`.`cscart_categories`.`usergroup_ids`)) and (`webmarco`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}