You can force a Clustered Index Seek by adding a seemingly superfluous WHERE clause that searches for values in that index between two values.

For example, if the clustered index was on a field called StateId and StateId was a TINY INT then we could write add a WHERE clause that says

WHERE StateId BETWEEN 0 AND 255

You can get a performance boost this way but a clustered index seek DOES NOT always result in a lower cost query. You have to experiment with your application to see what the affect is.