SELECT /* CodeRevisionListView::getRevCount <ip> */ COUNT( DISTINCT cr_id ) AS rev_count FROM `code_rev` LEFT JOIN `code_comment` ON ((cc_repo_id = cr_repo_id AND cc_rev_id = cr_id)) WHERE cr_repo_id = '1' LIMIT 1
Full list at P8182, creating 1052 20+ second queries on mediawikiwiki (s3).
The extension should be fixed to avoid creating long running queries or (it says here it should no longer be used on WMF: https://www.mediawiki.org/wiki/Extension:CodeReview ), fully deprecated from WMF infrastructure and undeployed.