SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(251, 252, 253) 
  AND category_id != 264

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "9.25"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "ALL",
      "rows_examined_per_scan": 84,
      "rows_produced_per_join": 22,
      "filtered": "27.00",
      "cost_info": {
        "read_cost": "6.98",
        "eval_cost": "2.27",
        "prefix_cost": "9.25",
        "data_read_per_join": "59K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "((`mobikul_delivery_boy_livedemo`.`cscart_categories`.`parent_id` in (251,252,253)) and (`mobikul_delivery_boy_livedemo`.`cscart_categories`.`category_id` <> 264))"
    }
  }
}