SELECT 
  a.category_id 
FROM 
  cscart_categories as a 
  LEFT JOIN cscart_categories as b ON b.category_id IN (3155) 
WHERE 
  a.id_path LIKE CONCAT(b.id_path, '/%')

Query time 0.00611

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "867.78"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "b",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY",
            "p_category_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "category_id"
          ],
          "key_length": "3",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.10",
            "prefix_cost": "0.00",
            "data_read_per_join": "2K"
          },
          "used_columns": [
            "category_id",
            "id_path"
          ]
        }
      },
      {
        "table": {
          "table_name": "a",
          "access_type": "index",
          "key": "id_path",
          "used_key_parts": [
            "id_path"
          ],
          "key_length": "767",
          "rows_examined_per_scan": 7821,
          "rows_produced_per_join": 868,
          "filtered": "11.11",
          "using_index": true,
          "cost_info": {
            "read_cost": "85.68",
            "eval_cost": "86.89",
            "prefix_cost": "867.78",
            "data_read_per_join": "2M"
          },
          "used_columns": [
            "category_id",
            "id_path"
          ],
          "attached_condition": "(`maniamall_cscart`.`a`.`id_path` like <cache>(concat('290/3118/3155','/%')))"
        }
      }
    ]
  }
}

Result

category_id
23734
3156
3160
3161
3162
3173
3175
3176
3195
3196
3197
3211
3213
3214
3221
3250
3255
3280
3288
3289
3290
3302
3304
3316
3340
3342
3383
3388
3405
3413
7889
7905
7906
7907
8082
8095
8122