SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    30300, 30577, 2329, 2330, 2219, 3116, 
    3001, 2331, 3111, 2220, 3657, 2322, 
    2590, 2333, 3107, 2336, 3572, 2284, 
    3102, 2561, 2230, 311, 3117, 3110, 1931, 
    2723, 2637, 28751, 30470, 29387, 29624, 
    30465, 30466, 30462, 30467, 29181, 
    13059, 13024, 28699, 13026, 2715, 28752, 
    12980, 12940, 12938, 12939, 28664, 
    12944, 29175, 29180, 29179, 29707, 
    13029, 30461, 30541, 30543, 12941, 
    29010, 12981, 12942, 13025, 29024
  )

Query time 0.00082

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "14.47"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 71,
      "rows_produced_per_join": 71,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "7.37",
        "eval_cost": "7.10",
        "prefix_cost": "14.47",
        "data_read_per_join": "184K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`maniamall_cscart`.`cscart_categories`.`parent_id` in (30300,30577,2329,2330,2219,3116,3001,2331,3111,2220,3657,2322,2590,2333,3107,2336,3572,2284,3102,2561,2230,311,3117,3110,1931,2723,2637,28751,30470,29387,29624,30465,30466,30462,30467,29181,13059,13024,28699,13026,2715,28752,12980,12940,12938,12939,28664,12944,29175,29180,29179,29707,13029,30461,30541,30543,12941,29010,12981,12942,13025,29024))"
    }
  }
}

Result