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 = 7318 
WHERE 
  cscart_products_categories.product_id IN (
    90287, 90176, 90192, 90309, 90236, 90241, 
    85960, 90235, 90240, 90225, 90183, 
    90234, 90239, 90224, 90199, 90173, 
    90308, 90223, 90278, 90286, 90198, 
    90222, 90221, 90197, 90205, 90216, 
    90220, 90191, 90277, 91538, 91539, 
    90210, 90233, 91536, 91537, 90190, 
    90182, 90172, 90276, 90204, 90215, 
    90209, 90232, 90196, 90189, 94081, 
    94082, 94085, 94088, 94089, 94090, 
    94093, 94095, 94096, 94097, 94098, 
    94099, 94116, 94118, 96193, 96194, 
    100923, 100924, 100925, 100926, 100927, 
    100930, 100931, 100932, 100933, 100934, 
    100935, 100936, 100937, 100938, 100939, 
    100940, 100941, 100942, 100943, 100946, 
    100947, 100949, 100950, 100951, 100952, 
    100953, 100954, 100955, 100956, 100957, 
    100958, 100959, 100960, 100961, 100962
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01454

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "173.13"
    },
    "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": 192,
            "rows_produced_per_join": 192,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "19.20",
              "prefix_cost": "38.73",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (90287,90176,90192,90309,90236,90241,85960,90235,90240,90225,90183,90234,90239,90224,90199,90173,90308,90223,90278,90286,90198,90222,90221,90197,90205,90216,90220,90191,90277,91538,91539,90210,90233,91536,91537,90190,90182,90172,90276,90204,90215,90209,90232,90196,90189,94081,94082,94085,94088,94089,94090,94093,94095,94096,94097,94098,94099,94116,94118,96193,96194,100923,100924,100925,100926,100927,100930,100931,100932,100933,100934,100935,100936,100937,100938,100939,100940,100941,100942,100943,100946,100947,100949,100950,100951,100952,100953,100954,100955,100956,100957,100958,100959,100960,100961,100962))"
          }
        },
        {
          "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",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 192,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "48.00",
              "eval_cost": "19.20",
              "prefix_cost": "105.93",
              "data_read_per_join": "3K"
            },
            "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": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 9,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "48.00",
              "eval_cost": "0.96",
              "prefix_cost": "173.13",
              "data_read_per_join": "25K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}