Yes, I guess it would be possible. For instance:
$username = "14c4b06b824ec593239362517f538b29";
$password = "1a1dc91c907325c69271ddf0c944bc72";
$host = "0a137b375cc3881a70e186ce2172c8d1";
$database = "2d07fad78478d88ebafdc581a91696bf";
mysql_connect(mcrypt_decrypt($host,$key,$foo), mcrypt_decrypt($username,$key,$foo), mcrypt_decrypt($password,$key,$foo)) or die("Error connecting to Database!");
mysql_select_db($database) or die("Cannot select database!");
If someone compromised this code, they would know the function needed to reverse the encryption as well as the key. You will have accomplished nothing.