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 = 7313 
WHERE 
  cscart_products_categories.product_id IN (
    98393, 98394, 98395, 98396, 98397, 98398, 
    98399, 98400, 98401, 98402, 98403, 
    98404, 98405, 98406, 98411, 98412, 
    98413, 98421, 98422, 98424, 98425, 
    98426, 98427, 98428, 98429, 98432, 
    98433, 98434, 98435, 98436
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00160

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "63.86"
    },
    "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": 112,
            "rows_produced_per_join": 112,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "11.50",
              "eval_cost": "11.20",
              "prefix_cost": "22.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (98393,98394,98395,98396,98397,98398,98399,98400,98401,98402,98403,98404,98405,98406,98411,98412,98413,98421,98422,98424,98425,98426,98427,98428,98429,98432,98433,98434,98435,98436))"
          }
        },
        {
          "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": "28.00",
              "eval_cost": "0.56",
              "prefix_cost": "61.90",
              "data_read_per_join": "14K"
            },
            "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": 5,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.40",
              "eval_cost": "0.56",
              "prefix_cost": "63.86",
              "data_read_per_join": "89"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
98393 7341,7342,7343,7157M
98394 7341,7342,7343,7157M
98395 7341,7342,7343,7157M
98396 7341,7342,7343,7157M
98397 7341,7342,7343,7157M
98398 7341,7342,7343,7157M
98399 7341,7342,7343,7157M
98400 7341,7342,7343,7157M
98401 7341,7342,7343,7157M
98402 7341,7342,7343,7157M
98403 7341,7342,7343,7157M
98404 7341,7342,7343,7157M
98405 7341,7342,7343,7157M
98406 7341,7342,7343,7157M
98411 7341,7342,7343,7157M
98412 7341,7342,7343,7157M
98413 7341,7342,7343,7157M
98421 7313,7338,7219M 0
98422 7341,7342,7343,7157M
98424 7313,7338,7219M 0
98425 7313,7338,7219M 0
98426 7313,7338,7219M 0
98427 7341,7342,7343,7157M
98428 7313,7338,7219M 0
98429 7341,7342,7343,7157M
98432 7313,7338,7219M 0
98433 7341,7342,7343,7157M
98434 7313,7338,7219M 0
98435 7341,7342,7343,7157M
98436 7313,7338,7219M 0