Having in mind your infrastructure scale, as well as, the fact that both of the roles (SQL-server, VeeamONE) are deployed on this server, I wouldn’t say that the CPU rate (30-50%) you see is that high - It's expected, actually.
As a workaround for decreasing CPU rate, it might be worth moving SQL server to a separate machine.
Furthermore, what instance of SQL-server is being used in your case?
You should be aware that Express edition does have a number of limitations covered here
Hope this helps.