How to check if a claim link is already been claimed or not?

Hello,
I have a project which dynamically retrieve POAP links inside a QR Code (only one). When the user scans the QrCode, it already redirects the user to its poap link claiming site.
The thing i'm struggling on is this:
If i have this link ->http://POAP.xyz/claim/example, how can i verify if "example" is already been minted?
I cannot retrieve any kind of informations about address, email or something else, the only thing we know is the event information, because we'll create it.

I was checking inside the APIs but i didn't find anything similar to what i need, what i was going to implement, is a scheduler that every X minutes will go validate the "example" and if it is not already minted it will be available again for scans.
Thanks a lot
Dario