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 = 7211 
WHERE 
  cscart_products_categories.product_id IN (
    98808, 98809, 98810, 98811, 98812, 98813, 
    98814, 98874, 98875, 98876, 98877, 
    99056, 99057, 99058, 99059, 99060, 
    99061, 99062, 99063, 99064, 99065, 
    99067, 99111, 99112
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00153

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "53.07"
    },
    "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": 93,
            "rows_produced_per_join": 93,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.59",
              "eval_cost": "9.30",
              "prefix_cost": "18.89",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (98808,98809,98810,98811,98812,98813,98814,98874,98875,98876,98877,99056,99057,99058,99059,99060,99061,99062,99063,99064,99065,99067,99111,99112))"
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "23.25",
              "eval_cost": "0.47",
              "prefix_cost": "51.44",
              "data_read_per_join": "12K"
            },
            "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.16",
              "eval_cost": "0.47",
              "prefix_cost": "53.07",
              "data_read_per_join": "74"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
98808 7241,7309,7346,7208M
98809 7241,7309,7346,7208M
98810 7241,7309,7346,7208M
98811 7241,7309,7346,7208M
98812 7241,7309,7346,7208M
98813 7241,7309,7346,7208M
98814 7241,7309,7346,7208M
98874 7241,7309,7346,7208M
98875 7241,7309,7346,7208M
98876 7241,7309,7346,7208M
98877 7241,7309,7346,7208M
99056 7241,7309,7346,7208M
99057 7241,7309,7346,7208M
99058 7241,7309,7346,7208M
99059 7241,7309,7346,7208M
99060 7241,7309,7346,7208M
99061 7241,7309,7346,7208M
99062 7241,7309,7346,7208M
99063 7241,7309,7346,7208M
99064 7241,7309,7346,7208M
99065 7241,7309,7346,7208M
99067 7241,7309,7346,7208M
99111 7345,7347,7259M
99112 7320,7260M