SELECT 
  * 
FROM 
  cscart_pincodes 
WHERE 
  status = 'A' 
ORDER BY 
  LENGTH(pincode) DESC

Query time 0.09686

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5632.20"
    },
    "ordering_operation": {
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "2736.40"
      },
      "table": {
        "table_name": "cscart_pincodes",
        "access_type": "ALL",
        "rows_examined_per_scan": 27364,
        "rows_produced_per_join": 2736,
        "filtered": "10.00",
        "cost_info": {
          "read_cost": "2622.17",
          "eval_cost": "273.64",
          "prefix_cost": "2895.81",
          "data_read_per_join": "6M"
        },
        "used_columns": [
          "pincode_id",
          "status",
          "type",
          "pincode",
          "time",
          "note"
        ],
        "attached_condition": "(`s2cart`.`cscart_pincodes`.`status` = 'A')"
      }
    }
  }
}