SELECT 
  * 
FROM 
  ushop_csc_product_questions_posts 
WHERE 
  parent_id IN ('2') 
  AND status IN ('A') 
ORDER BY 
  timestamp ASC

Query time 0.00070

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.75"
    },
    "ordering_operation": {
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "1.00"
      },
      "table": {
        "table_name": "ushop_csc_product_questions_posts",
        "access_type": "ALL",
        "rows_examined_per_scan": 5,
        "rows_produced_per_join": 1,
        "filtered": "20.00",
        "cost_info": {
          "read_cost": "0.65",
          "eval_cost": "0.10",
          "prefix_cost": "0.75",
          "data_read_per_join": "1K"
        },
        "used_columns": [
          "post_id",
          "parent_id",
          "id_path",
          "product_id",
          "company_id",
          "timestamp",
          "status",
          "user_id",
          "user_name",
          "email",
          "lang_code",
          "post",
          "email_timestamp"
        ],
        "attached_condition": "((`marketplace`.`ushop_csc_product_questions_posts`.`parent_id` = 2) and (`marketplace`.`ushop_csc_product_questions_posts`.`status` = 'A'))"
      }
    }
  }
}