PHP - 如果条件为真，我将如何进行循环，没有崩溃

I am trying to do a while loop to keep checking to see if the strings match, if the strings match than it will make the variable true, if not it will give the loop a little break. How can i go about doing this so it doesn't crash my whole server.

     do {
        $Blurb =json_decode($RBLXClass->getBlurb($RBLXClass->GetUserID($LT->RobloxAccount))); 
        if (preg_match('/\b'.$GETVerifyToken.'\b/', $Blurb->data->blurb)) {
            $foundToken = true;
        } else {
            sleep(2);
        }
    } while ($foundToken == false);