Can db query handle start transaction and commit?

Using InnoDB tables, if I setup my own class query in the models folder to extend PHPDS_query, can it handle an sql with START TRANSACTION and COMMIT? I need to lock a row in a table to read a value and then update the value. The value read needs to be unique, so I use the FOR UPDATE to lock it, then update it, then commit to unlock.

Will the example below cause any problems or should it function exactly as shown/intended?

Example:
class MyPlugin_doQuery extends PHPDS_query
{
  protected $sql = "
    START TRANSACTION;
    SELECT counter FROM _db_MyPlugin_table WHERE id=1 FOR UPDATE;
    UPDATE _db_MyPlugin_table SET counter = counter + 1 WHERE id=1;
    COMMIT;
  ";

  public function invoke($parameters)
  {
    $example_array = parent::invoke();
    //Do some stuff
    return;
  }
}