Macrium recently shifted to a for new customers (to support ongoing development), but they still offer perpetual licenses for legacy versions.

The phrase "Macrium Reflect key exclusive" largely points to a market that no longer exists. Macrium has stopped selling the product you are likely looking for. While keys exist for legacy users, attempting to find "exclusive" keys online is a security hazard. For a safe and modern solution, users should look toward Macrium's free Site Manager edition or a competitor product.