Hey reddit, do psn cards have expiration dates?

Hey guys, I went to Europe 3 months ago and bought a psn card there. Yesterday I finally opened it to buy Scott Pilgrim vs. The World however, I got a message saying that the code was either incorrect or no longer valid. I'm not sure if it's because I'm in China(My psn account is european). Anyway, I'm gonna try it later on today and if it doesn't work I'll give up and give away the code.

Update: I gave it another try and it finally worked after a few attempts. I'm not sure why it did that but finally I'll be able to play Scott Pilgrim. :D