Problem with SQL query that takes a long time to execute

[Idea-ahead]

After the last forum update (4.7.19) on my server, there was a problem with a SQL query that takes a very long time to execute. It is most visible in large topics with more than 500 replies. Increasing the amount of RAM or CPU does not help much.

/psxekstrema::psxmoder::IPS\Content_Item::_comments:2166/ SELECT forums_posts., author., author_pfields.* FROM ibf_forums_posts AS forums_posts  LEFT JOIN ibf_core_members AS author ON author.member_id = forums_posts.author_id  LEFT JOIN ibf_core_pfields_content AS author_pfields ON author_pfields.member_id=author.member_id WHERE forums_posts.topic_id=112736 AND (forums_posts.queued IN(0,2)) ORDER BY post_date asc LIMIT 0,25