Unique Token Generator

Token.php

<?php

class Token
{
    public static function generate()
    {
        $microtime = microtime(true);
        $microtimeString = (string)number_format($microtime, 6, '.', '');
        if (!strpos($microtimeString, '.'))
            $microtimeString = $microtimeString . '.0';
        $now = \DateTime::createFromFormat('U.u', $microtimeString);
        $now->setTimezone(new \DateTimeZone('Europe/Budapest'));
        $datetime = $now->format("Ymd-His-u");
        $bytes = openssl_random_pseudo_bytes(8);
        return md5($datetime) . bin2hex($bytes);
    }
}

echo Token::generate();
exit;

//TEST
$tokens = [];
for ($i = 0; $i < 50000; $i++) {
    $token = Token::generate();
    if (!in_array($token, $tokens))
        $tokens[] = $token;
    else
        die('UNIQUE ERROR' . PHP_EOL);
    if (strlen($token) != 48)
        die('LENGTH ERROR' . PHP_EOL);
}

echo 'OK' . PHP_EOL;