Can I Use a Single License Key for Two Hypervisors

Hi,

I have downloaded ESXi 6.0 and ESXi 6.5.0a from my VMware login. But I have a same key for both versions. My question is can I install ESXi 6.0 in one physical server and ESXi 6.5.0a on another physical server using this same license key? Will it violate the VMware license if I use this same key on Two physical servers which has different VMware versions?

Thanks