looks like this sql query works slow
SELECT DISTINCT p.manufacturer_id, m.name
FROM ac_products p
LEFT JOIN ac_manufacturers m ON p.manufacturer_id = m.manufacturer_id
WHERE p.product_id IN (SELECT DISTINCT p2c.product_id
FROM ac_products_to_categories p2c
INNER JOIN ac_products p ON p.product_id = p2c.product_id
WHERE p.status = '1' AND p2c.category_id IN (65, 326, 805));
can you try to run it in phpmyadmin and post execution time here?