Slow database queries by plugin, slows down website

Slow database queries by this plugin are being reported by the Query Monitor plugin, slowing down the website:

select distinct p.post_author,u.user_login from wp_posts p
LEFT JOIN wp_users u on p.post_author=u.ID where p.post_status="publish" and p.post_type="post"
sfmBasicActions->sfmListActiveRss()
Plugin: feedburner-alternative-and-rss-redirect 135 0.1157