zlacker

I would access the table through a view that had that query built into it.

create table all_items(id integer, value text, expires timestamp);

create index all_item_expiry on all_items(expires);

create view items as (select id, value, expires from all_items where expires > now());

Then you can treat items as your base table and postgres neatly allows INSERT/UPDATE/DELETE from it. You'll need a job to clean up expires < now() items but it can be done at whatever arbitrary interval you like, could even be a trigger in PG if you were feeling spicy.