I have been buying resale keys for office for a while now. Usually less than $5. But most of them stop working after 1-2 years. Is there anyway to validate that

I have been buying resale keys for office for a while now. Usually less than $5. But most of them stop working after 1-2 years. Is there anyway to validate that a key you are purchasing isn't part of some corporate unlimited plan that will eventually be revoked?