Problem with some query

[DARKF3D3]

# Wed Feb 2 04:13:48 2011
# Query_time: 7.121025 Lock_time: 1.865858 Rows_sent: 1 Rows_examined: 1
use -----------------;
SELECT *
FROM `ps_product` a WHERE a.`id_product` = 31 LIMIT 1


# Wed Feb 2 04:14:23 2011
# Query_time: 4.588940 Lock_time: 0.849450 Rows_sent: 1 Rows_examined: 1
use -----------------;
SELECT p.`id_tax`, t.`rate`
FROM `ps_product` p
LEFT JOIN `ps_tax` AS t ON t.`id_tax` = p.`id_tax`
WHERE p.`id_product` = 31 LIMIT 1


# Wed Feb 2 04:57:22 2011
# Query_time: 4.201742 Lock_time: 2.026375 Rows_sent: 0 Rows_examined: 1
use -----------------;
UPDATE `ps_page_viewed`
SET `counter` = `counter` + 1
WHERE `id_date_range` = 143
AND `id_page` = 196


How it is possible that these queries are so slow? There a way to speed up them?


Thanks