Fix a DB query that's slowing down the site big time

Website is built on OPENCART 3.0 with Fastor theme.. Site (and admin) is loading very slow and sometimes throws various HTTP timeout errors (500,504)... i had faced similar kind of problem on a previous site, and had set up a slow_query_log because Opencart has a DB query that fetches product total count that's taking >10 seconds everytime it loads. And it also clogs the website speed and is bringing it down: 1) DB QUERY SELECT COUNT(DISTINCT p.product_id) AS total FROM oc_category_path cp LEFT JOIN oc_product_to_category p2c ON (cp.category_id = p2c.category_id) LEFT JOIN oc_product p ON (p2c.product_id = p.product_id) LEFT JOIN oc_product_description pd ON (p.product_id = pd.product_id) LEFT JOIN oc_product_to_store p2s ON (p.product_id = p2s.product_id) WHERE pd.language_id = '1' AND [login to view URL] = '1' AND p.date_available <= NOW() AND p2s.store_id = '0' AND cp.path_id = '222'; Need to identify which FILE is calling this query and fix it in backend. The problem is happening because I have > 25000 products on my site.. I just want to know what other precautions to take ( eg.. is there any other queries that need to be taken care of) so that I can continue to add more products to my website.. 2) [login to view URL] The above Blog says that three files in catalog/controller needs to be fixed. But these files are not there in my web-files under the directories specified. Also, there are some other forums that say it's the MODEL file and not the CONTROLLER file that needs to be changed. Also, I want to know if there's any file in the ADMIN MVC files that need to be changed, because admin is also not loading properly?