Is this after the upgrade to the new version or you have installed it newly?
I have the simular problem.
Query Monitor shows a big delays when making DB requests like
select * from wp_WP_SEO_Cache where ID='325';
Please update to version 3.3 and go to general options and click the button “Optimize tables”
I think that it is fixed now, please reinstall the plugin and check.
To update or reinstall the plugin do the following steps:
1- Go to “Options” tab and make sure the check “Keep redirection data after uninstall the plugin ….” is checked.
2- Deactivate and delete the old version.
3- install the new version.
Please let me know if works for you …