SELECT 
  cscart_products_categories.product_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, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  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_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 10437 
WHERE 
  cscart_products_categories.product_id IN (
    427214, 390160, 389481, 389483, 427216, 
    388722, 427215, 388890, 390264, 389298, 
    389462, 388844, 390175, 389444, 388558, 
    388967, 389836, 388455, 390211, 388642, 
    415655, 389567, 389347, 415501, 389591, 
    389854, 390309, 390251, 390226, 389834, 
    388395, 388497, 389163, 388912, 415654, 
    415656, 415382, 388942, 415377, 415495, 
    390245, 389852, 389054, 390237, 415469, 
    390205, 390305, 389833, 415531, 389229, 
    389487, 415663, 389432, 388953, 390193, 
    388447, 388963, 390223, 388957, 389431, 
    388574, 389542, 388453, 390122, 426897, 
    389873, 390161, 390273, 389522, 388958, 
    390135, 389263, 389558, 389452, 388422, 
    390224, 388479, 388513, 390192, 390209, 
    390257, 415496, 389507, 388544, 388454, 
    390198, 389359, 390316, 389532, 390129, 
    390164, 390243, 389428, 389827
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00264

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "264.35"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 94,
            "rows_produced_per_join": 94,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "19.95",
              "eval_cost": "18.80",
              "prefix_cost": "38.75",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`webmarco`.`cscart_products_categories`.`product_id` in (427214,390160,389481,389483,427216,388722,427215,388890,390264,389298,389462,388844,390175,389444,388558,388967,389836,388455,390211,388642,415655,389567,389347,415501,389591,389854,390309,390251,390226,389834,388395,388497,389163,388912,415654,415656,415382,388942,415377,415495,390245,389852,389054,390237,415469,390205,390305,389833,415531,389229,389487,415663,389432,388953,390193,388447,388963,390223,388957,389431,388574,389542,388453,390122,426897,389873,390161,390273,389522,388958,390135,389263,389558,389452,388422,390224,388479,388513,390192,390209,390257,415496,389507,388544,388454,390198,389359,390316,389532,390129,390164,390243,389428,389827))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "webmarco.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 94,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "94.00",
              "eval_cost": "18.80",
              "prefix_cost": "151.55",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "94.00",
              "eval_cost": "0.94",
              "prefix_cost": "264.35",
              "data_read_per_join": "27K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}