A product key does not have a lifespan.

Is Windows 10 license lifetime?

Windows 10 Home is currently available with a lifetime licence for one PC, so it can be transferred when a PC is replaced.

How long does a Windows key last?

Normally, an Open Business license agreement is good for two years with an Open Value licensing agreement. This is, however, renewable. Prior to its termination, you will receive notification from Microsoft to renew your license at least 45.