$data = 'abc:def@ghi:jkl';

$user = explode(':', explode('@', $data)[0])[0];
$pass = explode(':', explode('@', $data)[0])[1];
$ip = explode(':', explode('@', $data)[1])[0];
$proxy = explode(':', explode('@', $data)[1])[1];

print_r($user);
print_r($pass);
print_r($ip);
print_r($proxy);