Validation in laravel 5.1

as would do this in laravel ? I need to pass this condition laravel

$query = mysql_query("SELECT * FROM citas WHERE especialidad='".$especialidad."'AND doctor='".$doctor."'AND fecha ='".$fecha."' AND hora = '".$hora."'" , $con);

if ($existe = mysql_fetch_object($query)) 
{


}else{}</code>

via Chebli Mohamed