SELECT 
  category_id, 
  parent_id 
FROM 
  ushop_categories 
WHERE 
  parent_id IN(
    292, 274, 272, 276, 273, 282, 295, 294, 
    268, 281, 280, 288, 300, 301, 278, 277, 
    287, 265, 291, 296, 290, 283, 298, 270, 
    269, 299, 285, 275, 302, 303, 286, 284, 
    267, 293, 279, 289, 266, 271, 297, 333, 
    304, 305, 306, 307, 309, 310, 311, 312, 
    316, 317, 318, 319, 321, 323, 325, 329, 
    330, 331, 334
  ) 
  AND category_id != 264

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "ushop_categories",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY", "parent", "p_category_id"],
          "rows": 61,
          "filtered": 100,
          "attached_condition": "ushop_categories.parent_id in (292,274,272,276,273,282,295,294,268,281,280,288,300,301,278,277,287,265,291,296,290,283,298,270,269,299,285,275,302,303,286,284,267,293,279,289,266,271,297,333,304,305,306,307,309,310,311,312,316,317,318,319,321,323,325,329,330,331,334) and ushop_categories.category_id <> 264"
        }
      }
    ]
  }
}