sql request syntax

Hello, is my syntax correct ? I would like to retrive the post that has a metakey ‘intro’ having ‘1’ as value.
This is from plugin get-a-post, but i’m not sure it’s working.

SELECT * FROM wp_posts, wp_postmeta WHERE post_date <= ‘2007-09-29 02:41:16’ AND ID = post_id AND meta_key = ‘intro’ AND meta_value = 1 ORDER BY post_date DESC LIMIT 1