Slow repetitive SQL queries

We're seeing queries of this form end up in the MySQL slow query log:

	  SELECT title, feed, fppid FROM feed_path_publisher 
	   WHERE path_prefix = LEFT("node/20060", LENGTH(path_prefix)) 
	      OR path_prefix = LEFT("node/20060", LENGTH(path_prefix))
	      OR path_prefix = LEFT("node/20060", LENGTH(path_prefix))
	ORDER BY weight, path_prefix;

In our case, node/20060 is our front page.

I wonder if the restrictions could be uniqued, so that we don't see duplication there?

Also, is it intentional that an empty path_prefix will match all entries in {feed_path_publisher}?