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 (
    88005, 87939, 87989, 87943, 87973, 87999, 
    90808, 87965, 88014, 88020, 92893, 
    92894, 93002, 93003, 93004, 93005, 
    93006, 93007, 93008, 93009, 93010, 
    93011, 93012, 93013, 93014, 93015, 
    93341, 93342, 93343, 93344
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.02079

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "90.30"
    },
    "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": 100,
            "rows_produced_per_join": 100,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.30",
              "eval_cost": "10.00",
              "prefix_cost": "20.30",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (88005,87939,87989,87943,87973,87999,90808,87965,88014,88020,92893,92894,93002,93003,93004,93005,93006,93007,93008,93009,93010,93011,93012,93013,93014,93015,93341,93342,93343,93344))"
          }
        },
        {
          "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": 100,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "25.00",
              "eval_cost": "10.00",
              "prefix_cost": "55.30",
              "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": "25.00",
              "eval_cost": "0.50",
              "prefix_cost": "90.30",
              "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
87939 7261M,7349
87943 7349,7261M
87965 7349,7261M
87973 7349,7261M
87989 7349,7261M
87999 7349,7261M
88005 7349,7261M
88014 7349,7261M
88020 7349,7261M
90808 7349,7261M
92893 7208M,7346,7309,7241
92894 7208M,7241,7309,7346
93002 7346,7241,7309,7208M
93003 7346,7309,7208M,7241
93004 7241,7309,7346,7208M
93005 7241,7208M,7309,7346
93006 7241,7208M,7309,7346
93007 7241,7309,7208M,7346
93008 7309,7346,7208M,7241
93009 7309,7241,7346,7208M
93010 7309,7346,7208M,7241
93011 7208M,7346,7241,7309
93012 7241,7208M,7309,7346
93013 7208M,7309,7241,7346
93014 7208M,7309,7241,7346
93015 7241,7208M,7346,7309
93341 7241,7346,7208M,7309
93342 7346,7208M,7241,7309
93343 7241,7208M,7346,7309
93344 7346,7241,7208M,7309