Help optimizing a query

[rossco_2005]

I need help with optimizing queries with indexes.
I try my best but whatever combinations I try the query is slow.
Here is an example query:

SELECT COUNT(nzb.threadid) as threads 
FROM thread as thread
LEFT JOIN nzb as nzb
	ON nzb.threadid=thread.threadid

WHERE thread.forumid IN (80,120,106,108,107)
	AND sticky = 0	
	AND visible IN (0,1,2)

OR

SELECT COUNT(nzb.threadid) as threads 
FROM thread as thread
LEFT JOIN nzb as nzb
	ON nzb.threadid=thread.threadid

WHERE thread.forumid IN (80,120,106,108,107)
	AND sticky = 0	
	AND visible IN (0,1,2)
	 AND thread.iconid IN(30,34,36,67,73,99,100,102,104,75,76,78,97,98,107,106,33)

They don't need to have the sticky or visible columns in the WHERE, that was just something I thought might help me to hit the forumid index in thread table.

Anyway what's the recommended indexes keeping in mind this query ^.

Thanks a lot for any help you can give me.