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 = 7148 
WHERE 
  cscart_products_categories.product_id IN (
    91791, 91792, 91793, 91794, 91795, 92254, 
    92501, 92502, 92503, 92504, 92505, 
    92506, 92507, 88904, 86858, 84701, 
    88959, 88960, 88962, 82353, 92192, 
    92193, 92194, 92195, 92196, 92204, 
    92205, 92206, 92207, 92208, 92209, 
    92442, 92443, 92448, 92001, 92147, 
    92148, 92149, 92349, 92350, 92351, 
    92352, 85647, 85801, 85802, 91938, 
    84700, 86864
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00271

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "101.34"
    },
    "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": 178,
            "rows_produced_per_join": 178,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "18.12",
              "eval_cost": "17.80",
              "prefix_cost": "35.92",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (91791,91792,91793,91794,91795,92254,92501,92502,92503,92504,92505,92506,92507,88904,86858,84701,88959,88960,88962,82353,92192,92193,92194,92195,92196,92204,92205,92206,92207,92208,92209,92442,92443,92448,92001,92147,92148,92149,92349,92350,92351,92352,85647,85801,85802,91938,84700,86864))"
          }
        },
        {
          "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": 8,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "44.50",
              "eval_cost": "0.89",
              "prefix_cost": "98.22",
              "data_read_per_join": "23K"
            },
            "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')))"
          }
        },
        {
          "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": 8,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.23",
              "eval_cost": "0.89",
              "prefix_cost": "101.34",
              "data_read_per_join": "142"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}