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 = 7184 
WHERE 
  cscart_products_categories.product_id IN (
    98731, 98732, 98733, 98734, 98735, 98736, 
    98737, 98750, 98751, 98752, 98753, 
    98754, 98755, 98756, 98757, 98759, 
    98769, 98770, 98771, 98772, 98897, 
    99020, 99021, 99022, 99023, 99024, 
    99025, 99066, 99508, 99509, 99510, 
    99512, 99513, 99514, 99516, 99517, 
    99518, 99528, 99562, 99563, 99564, 
    99565, 99653, 99654, 99655, 99656, 
    99657, 99658
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00222

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "63.29"
    },
    "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": 111,
            "rows_produced_per_join": 111,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "11.40",
              "eval_cost": "11.10",
              "prefix_cost": "22.50",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (98731,98732,98733,98734,98735,98736,98737,98750,98751,98752,98753,98754,98755,98756,98757,98759,98769,98770,98771,98772,98897,99020,99021,99022,99023,99024,99025,99066,99508,99509,99510,99512,99513,99514,99516,99517,99518,99528,99562,99563,99564,99565,99653,99654,99655,99656,99657,99658))"
          }
        },
        {
          "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": "27.75",
              "eval_cost": "0.56",
              "prefix_cost": "61.35",
              "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": "1.39",
              "eval_cost": "0.56",
              "prefix_cost": "63.29",
              "data_read_per_join": "88"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}