SELECT 
  id_path 
FROM 
  categories 
WHERE 
  category_id IN (
    26, 203, 3279, 3283, 4034, 4051, 4071, 
    4073, 11842
  )

Query time 0.00082

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "4.07"
    },
    "table": {
      "table_name": "categories",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "p_category_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "category_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 9,
      "rows_produced_per_join": 9,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "3.17",
        "eval_cost": "0.90",
        "prefix_cost": "4.07",
        "data_read_per_join": "23K"
      },
      "used_columns": [
        "category_id",
        "id_path"
      ],
      "attached_condition": "(`goimagine`.`categories`.`category_id` in (26,203,3279,3283,4034,4051,4071,4073,11842))"
    }
  }
}