Checking = with timestamp field is slow

[Antony Paul <antonypaul24@xxxxxxxxx>]

Hi all,
   I have a table which have more than 200000 records. I need to get
the records which matches like this

where today::date = '2004-11-05';

This is the only condition in the query. There is a btree index on the
column today.
Is there any way to optimise it.

rgds
Antony Paul