Select with MD5 password returning empty

I'm using the query below to login, it was working normal with normal passwords, but now I'm migrating to the Md5 password, but this only giving invalid password, I believe it's my select that is with error "SELECT * FROM usuarios WHERE usu_login = '".$login."' and usu_senha = 'MD5(".$senha.")'"; more I can not see, what could it be?

include("conn_user.php");


$login= $_POST["login"];
$senha =$_POST["senha"];

$ users="SELECT * FROM users WHERE usu_login = '. $ login."' and username = '".MD5 ($ password).        $ result_users = mysql_query ($ users, $ conn_user);          $ u = mysql_fetch_object ($ result_users);           if (mysql_num_rows ($ result_users) == 1) {

$v_nome          = $u->usu_nome;
$v_senha         = $u->usu_senha;

echo"$v_nome";
echo"$v_senha";


}

In the database, the password is registered like this:

  

2171d30f75d516c10c2f

Already in the query what is happening is greater:

  

2171d30f75d516c10c2f4c79dd270542