SELECT 
  * 
FROM 
  cscart_abt__ut2_fly_menu_content 
WHERE 
  storefront_id = 1 
ORDER BY 
  position asc

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "read_sorted_file": {
      "filesort": {
        "sort_key": "cscart_abt__ut2_fly_menu_content.position",
        "table": {
          "table_name": "cscart_abt__ut2_fly_menu_content",
          "access_type": "ALL",
          "rows": 9,
          "filtered": 100,
          "attached_condition": "cscart_abt__ut2_fly_menu_content.storefront_id = 1"
        }
      }
    }
  }
}