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 = 7257 
WHERE 
  cscart_products_categories.product_id IN (
    97698, 97699, 97700, 97701, 97702, 97703, 
    97704, 97705, 97706, 97707, 97708, 
    97709, 97710, 97711, 97712, 98054, 
    98055, 98056, 98057, 98058, 98059, 
    98060, 98061, 98062, 98063, 98064, 
    98065, 98066, 98067, 98068
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01458

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "92.10"
    },
    "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": 102,
            "rows_produced_per_join": 102,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.50",
              "eval_cost": "10.20",
              "prefix_cost": "20.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (97698,97699,97700,97701,97702,97703,97704,97705,97706,97707,97708,97709,97710,97711,97712,98054,98055,98056,98057,98058,98059,98060,98061,98062,98063,98064,98065,98066,98067,98068))"
          }
        },
        {
          "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": 102,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "25.50",
              "eval_cost": "10.20",
              "prefix_cost": "56.40",
              "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": "25.50",
              "eval_cost": "0.51",
              "prefix_cost": "92.10",
              "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')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
97698 7261M,7349
97699 7260M,7320
97700 7260M,7320
97701 7260M,7320
97702 7260M,7320
97703 7261M,7349
97704 7258M
97705 7259M,7345,7347
97706 7260M,7320
97707 7208M,7241,7309,7346
97708 7208M,7241,7309,7346
97709 7208M,7241,7309,7346
97710 7208M,7241,7309,7346
97711 7208M,7241,7309,7346
97712 7208M,7241,7309,7346
98054 7208M,7241,7309,7346
98055 7208M,7241,7309,7346
98056 7208M,7241,7309,7346
98057 7208M,7241,7309,7346
98058 7208M,7241,7309,7346
98059 7208M,7241,7309,7346
98060 7208M,7241,7309,7346
98061 7208M,7241,7309,7346
98062 7208M,7241,7309,7346
98063 7208M,7241,7309,7346
98064 7208M,7241,7309,7346
98065 7208M,7241,7309,7346
98066 7208M,7241,7309,7346
98067 7208M,7241,7309,7346
98068 7208M,7241,7309,7346