Unique one time use URL

Hey folks,

I’ve been searching for solution to my problem.
Here is what I need:

I’ve got a simple landing page with a form. What I need is a way to create unique url’s for people I choose so only they can access this site and fill out the form. URL has to be active only for 7 days and once used, deactivated immediately. The unique URL’s should work a long, which means at the same time I can generate multiple URL’s.

The other way to approach this problem is to generate many passwords that I can send to people I choose. Same story – every password is unique and works only once. Page is password restricted and when user puts the password in it’s no longer active.

I’m really not type of guy who just wants solution given to him on a silver platter, but right now… I have my back against the wall and literally no time. Any help is appreciated. Thank you.