Since 2017-09-26 I have terrible problems with performance on my website.
Loading single post or any other page takes even 20s. I've been debugging it it found out, that the problems are DB queries.
For example this one is executing almost with every page load and takes about 36s:
SELECT t.*, tt.*, tr.object_id FROM az2_terms AS t INNER JOIN az2_term_taxonomy AS tt ON t.term_id = tt.term_id INNER JOIN az2_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ('znacka', 'model') AND tr.object_id IN (27130, 27290, 27822, 27899, 30862, 33536, 33721, 34901, 37448, 37482, 37496, 37522, 37572, 37580, 37742, 37750, 38160, 38165) ORDER BY t.name ASC
When it's executing for the second time, it's lamost instant. Since the 2017-09-26 I haven(t made any changes, only switched to HTTPS, could that be the problem?