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 (
    389137, 415660, 389200, 435303, 388788, 
    389835, 388510, 389810, 427217, 425347, 
    390290, 390241, 389859, 389060, 415383, 
    389208, 388646, 389352, 388796, 388698, 
    389460, 389091, 388735, 415385, 426890, 
    389205, 390141, 435215, 388655, 389361, 
    434573, 388392, 389207, 389812, 389043, 
    415499, 389198, 388465, 390112, 388429, 
    388746, 389482, 390168, 391773, 388927, 
    415727, 388576, 390200, 390126, 388653, 
    389832, 390111, 388379, 389174, 389536, 
    415473, 389494, 389500, 390240, 389571, 
    435214, 388421, 388520, 415523, 388384, 
    435297, 388742, 388675, 415513, 435291, 
    389504, 415704, 388803, 388946, 415533, 
    388858, 390293, 435292, 389363, 388710, 
    389527, 388677, 388854, 388435, 388593, 
    388423, 388591, 388717, 388979, 388624, 
    427198, 389476, 415315, 389216, 388458, 
    390239, 415504, 415472, 389524, 389100
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00312

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "286.76"
    },
    "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": 102,
            "rows_produced_per_join": 102,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "21.56",
              "eval_cost": "20.40",
              "prefix_cost": "41.96",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`webmarco`.`cscart_products_categories`.`product_id` in (389137,415660,389200,435303,388788,389835,388510,389810,427217,425347,390290,390241,389859,389060,415383,389208,388646,389352,388796,388698,389460,389091,388735,415385,426890,389205,390141,435215,388655,389361,434573,388392,389207,389812,389043,415499,389198,388465,390112,388429,388746,389482,390168,391773,388927,415727,388576,390200,390126,388653,389832,390111,388379,389174,389536,415473,389494,389500,390240,389571,435214,388421,388520,415523,388384,435297,388742,388675,415513,435291,389504,415704,388803,388946,415533,388858,390293,435292,389363,388710,389527,388677,388854,388435,388593,388423,388591,388717,388979,388624,427198,389476,415315,389216,388458,390239,415504,415472,389524,389100))"
          }
        },
        {
          "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": 102,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "102.00",
              "eval_cost": "20.40",
              "prefix_cost": "164.36",
              "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": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "102.00",
              "eval_cost": "1.02",
              "prefix_cost": "286.76",
              "data_read_per_join": "30K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}