Optimizing a Simple Select

I have a very simple select statement:

SELECT COUNT(*) as varTotal
FROM tbl_stat_master
WHERE stat_account = 173
AND stat_created 
BETWEEN '2012-11-01 00:00:00' 
AND '2012-12-01 00:00:00'

It's running on a table that has 36 Million records. I'd like to it be faster.

I have two indexes setup, one on stat_account and one on stat_created.

So first of all, is there something I should do to make the query faster? Like maybe COUNT(*) isn't a good idea, or there something better than BETWEEN?

And secondly, should I change my indexes? Make a combo index that includes account and created?

Or maybe you have another idea?

Thank you!