Avoiding mysql slow queries

Hello,
I have a mysql database
Our server is: 64 bit processor server running 4 CPUs with 4 GB of RAM...

when I checked mysql slow queries log, I found so many lines like this with query _time around 6 to 12 for most of the queries:

-----------
# Tue Mar 20 03:02:33 2007
# Query_time: 12 Lock_time: 0 Rows_sent: 1 Rows_examined: 1
use trials_data;
SELECT id, site, rank, title, description, keywords, category, reviews, ratings, clicks FROM table WHERE site = 'firstsite' LIMIT 1
-------------
# Tue Mar 20 05:01:21 2007
# Query_time: 4 Lock_time: 0 Rows_sent: 10 Rows_examined: 5210
use trials_data;
SELECT DISTINCT site FROM table WHERE ( site='shopping' OR title LIKE '%shopping%' OR keywords LIKE '%shopping%' OR description LIKE '%shopping%') ORDER BY rank LIMIT 40, 10
-------------
# Tue Mar 20 05:08:36 2007
# Query_time: 17 Lock_time: 7 Rows_sent: 1 Rows_examined: 5012
use trials_data;
SELECT COUNT(DISTINCT site) FROM cb_urls15 WHERE ( site='recipes' OR title LIKE '%recipes%' OR keywords LIKE '%recipes%' OR description LIKE '%recipes%')
-----------
Here
id=primary key
site=index
category=index

title, description, keyword, reviews are 'text' with around 300 characters each.
others are of VARCHAR

I dont understand why I am getting these queries slow though Rows_sent: 1 and Rows_examined: 1

Please inform me how to optimize these queries.

Thank you.

site='recipes' OR title LIKE '%recipes%' OR keywords LIKE '%recipes%' OR description LIKE '%recipes%'

That's bad right there.

When you use LIKE on a text field that has a lot of text in it (300 is a good chunk), with 5000 rows it has to go through each field, in each row, for each LIKE.

If you're trying to do searches, google for 'mysql fulltext'.

Thank you Aedrin,
I have implemented your suggestion, and now my site is running well without considerable slow queries.
Thanks.