SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    23006, 23007, 23008, 22997, 22995, 22994, 
    22996, 23002, 22998, 23003, 23000, 
    23004, 23009, 22999, 23005, 23001
  ) 
  AND category_id != 1

Query time 0.00005

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_categories",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "parent", "p_category_id"],
          "key": "parent",
          "key_length": "3",
          "used_key_parts": ["parent_id"],
          "rows": 16,
          "filtered": 100,
          "index_condition": "cscart_categories.parent_id in (23006,23007,23008,22997,22995,22994,22996,23002,22998,23003,23000,23004,23009,22999,23005,23001)",
          "attached_condition": "cscart_categories.category_id <> 1"
        }
      }
    ]
  }
}