you can run the following query in your SQL console:
select * from "SYS"."M_DATABASE";
from this you will get the revision number of your HANA Server. This revision number directly maps to the SP number, e.g. 1.00.51.XXXXXX will mean SP05, 1.00.31.XXXXXX will mean SP03.
Also going in Help -> about will give the version of your HANA Studio (your frontend) not the Database Version.