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 = 7247 
WHERE 
  cscart_products_categories.product_id IN (
    89173, 90321, 90322, 90325, 90324, 90326, 
    90323, 90329, 90330, 90331, 90333, 
    90334, 90337, 90338, 90339, 90340, 
    90341, 90342, 90345, 90346, 90347, 
    90348, 90328, 90332, 90335, 90336, 
    90343, 90344, 90327, 90317, 90319, 
    90320, 87388, 87387, 87389, 87383, 
    87384, 89612, 89613, 87386, 87382, 
    89611, 94119, 94120, 94121, 94122, 
    94123, 94124
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01250

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "95.70"
    },
    "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": 106,
            "rows_produced_per_join": 106,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.90",
              "eval_cost": "10.60",
              "prefix_cost": "21.50",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (89173,90321,90322,90325,90324,90326,90323,90329,90330,90331,90333,90334,90337,90338,90339,90340,90341,90342,90345,90346,90347,90348,90328,90332,90335,90336,90343,90344,90327,90317,90319,90320,87388,87387,87389,87383,87384,89612,89613,87386,87382,89611,94119,94120,94121,94122,94123,94124))"
          }
        },
        {
          "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": 106,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "26.50",
              "eval_cost": "10.60",
              "prefix_cost": "58.60",
              "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": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "26.50",
              "eval_cost": "0.53",
              "prefix_cost": "95.70",
              "data_read_per_join": "13K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}