// Pseudocode for checking token validity and expiration time
$token = $_GET['token'];
$query = "SELECT * FROM reset_tokens WHERE token = ? AND expires_at > NOW()";
$stmt = $pdo->prepare($query);
$stmt->execute([$token]);
$tokenData = $stmt->fetch();
if (!$tokenData) {
// Token is invalid or expired, show an error message
echo "Invalid or expired token. Please request a new password reset.";
} else {
// Token is valid, allow the user to reset their password
// Display the password reset form
}