Is It really any way to speed up the execution time
You are running
Select * from tblUsers and expecting it to be fast? You are selecting all columns and all rows from a table, so it will take its own time to return the result set. If there is a clustered index, an index scan would be used, and if the table is a heap, a table scan would be used.
If you want to increase the speed, you either have to add a WHERE clause to make query sargable or limit the number of columns, although the latter will not affect the execution time so much.
Also, if your data file lies on a fast storage (SSDs, Flash Drives, as compared to SATA disks), the query is likely to become faster.
Moral: If you are running
select * on a table, don't expect the query to be fast, it would take its own time to retrieve all rows. If you are on a production system, running
select * would really be a performance killer, so avoid it.