mysql user authentication for nodeftpd

I would like to use nodeftpd with mysql authentication, but the problem is connection.query() is async and script finishes before mysql returns results.

Although, I have worked out a solution already but it's a hack and not really a solution and is ugly. So how to use mysql to authenticate in the command:pass of the nodeftpd library

So its more of a how to asynch properly, probably!

conn.on('command:pass', function(pass, success, failure) {

    if(pass)
     con.query('select * from wp_users where user_login = ? and user_pass = ?',[username, pass], function(err, rows, fields){
        if(rows.length > 0  ){
            success();
            return;
        }else{
            failure();
            return;
        }
        console.log('yy');

    });
     console.log('xx');
     failure();
  });