syntax to use near 'key='fAWHVQXA1s3kGjWSN9yF3sWfpMAoq4VP''

bruger mysql v.5 og php v.5
jeg kør ?key=fAWHVQXA1s3kGjWSN9yF3sWfpMAoq4VP
<?php
include("../lang.php");
include ('../config.php');
$key = addslashes($_GET['key']);
$key_check_query = mysql_query("SELECT * FROM validate WHERE key='$key' ") or die(mysql_error());
$key_check_fetch = mysql_num_rows($key_check_query);
if($key_check_fetch != 0){
echo "<br><br>$key<br>&nbsp;&nbsp;";
} else {
echo "<br><br>Invalid key<br>&nbsp;&nbsp;";
exit();
}
?>

db ser sådan her ud

CREATE TABLE `validate` (
  `id` int(6) NOT NULL auto_increment,
  `key` varchar(32) NOT NULL,
  PRIMARY KEY  (`id`),
  UNIQUE KEY `key` (`key`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;