SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    2347, 2377, 2378, 2380, 2384, 2416, 2417, 
    2428, 2451, 2485, 2614, 2617, 2622, 
    2623, 2625, 2626, 2632, 2633, 2651, 
    2671, 2673, 2418, 2439
  ) 
  AND category_id != 414

Query time 0.00076

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "23.31"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "parent",
        "p_category_id"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 39,
      "rows_produced_per_join": 39,
      "filtered": "100.00",
      "index_condition": "(`s2cart`.`cscart_categories`.`parent_id` in (2347,2377,2378,2380,2384,2416,2417,2428,2451,2485,2614,2617,2622,2623,2625,2626,2632,2633,2651,2671,2673,2418,2439))",
      "cost_info": {
        "read_cost": "19.41",
        "eval_cost": "3.90",
        "prefix_cost": "23.31",
        "data_read_per_join": "138K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`s2cart`.`cscart_categories`.`category_id` <> 414)"
    }
  }
}