Make Link expire after X minutes
+https://stackoverflow.com/questions/39763567/make-link-expire-after-x-minutes

PHP – Show link expiration time in minutes
+https://stackoverflow.com/questions/30967616/php-show-link-expiration-time-in-minutes

Create unique link (one time click) with expiration time [closed]
+https://stackoverflow.com/questions/19384847/create-unique-link-one-time-click-with-expiration-time

+https://stackoverflow.com/questions/14719950/how-to-expire-the-activation-link-in-php

+http://ray.tookjai.net/index.php/2015/06/11/password/