SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    722, 714, 706, 715, 707, 723, 708, 703, 
    704, 716, 709, 724, 725, 726, 713, 717, 
    727, 728, 729, 718, 719, 720, 730, 710, 
    721, 705, 711, 712, 1297
  ) 
  AND category_id != 265

Query time 0.00099

JSON explain

{
  "query_block": {
    "select_id": 1,
    "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": 50,
      "filtered": 100,
      "index_condition": "cscart_categories.parent_id in (722,714,706,715,707,723,708,703,704,716,709,724,725,726,713,717,727,728,729,718,719,720,730,710,721,705,711,712,1297)",
      "attached_condition": "cscart_categories.category_id <> 265"
    }
  }
}

Result

category_id parent_id
706 705
707 705
708 705
709 705
710 705
711 705
713 712
721 712
714 713
715 713
716 713
717 713
718 713
719 713
720 713
722 721
723 721
724 721
725 721
726 721
727 721
728 721
729 721
730 721
1297 721