Large SQL statements kill our server

Hello,

we bought the auction tool, and urgently need support, since it just totally killed our server when the auctions reached there ending time. And we only had about 20 items and probably only about 15 people placing bids. Every 5 minutes one auction is ending.
We use the proxy bid.

Very obvious that this is because of very bad performing SQL statements.

All support contact channels seem not to work. How to really reach your “world class support”?!

We have the same problems like in this posts:
https://wordpress.org/support/topic/bidders-who-want-to-increase-their-proxy-bid-end-up-bidding-against-themselves?replies=1
https://wordpress.org/support/topic/online-auction-disaster-bidders-cant-access-website-5-hrs-before-auction-ends?replies=3

This is one of the SQL statement that kill the server:

SELECT wp_posts.* FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (3)
) AND wp_posts.post_type = ‘ultimate-auction’ AND ((wp_posts.post_status = ‘publish’)) AND ID IN(
SELECT post_id
FROM wp_postmeta
WHERE meta_key = ‘auction_bought_status’ AND meta_value = ‘bought’
UNION ALL
SELECT s3.post_id
FROM wp_wdm_bidders s1, wp_postmeta s3
WHERE s3.post_id = s1.auction_id AND s3.meta_value <= s1.bid AND s3.meta_key = ‘wdm_lowest_bid’ AND s1.bid=(SELECT MAX(s2.bid)
FROM wp_wdm_bidders s2
WHERE s1.auction_id = s2.auction_id)
UNION ALL
SELECT s3.post_id
FROM wp_postmeta s3
WHERE s3.meta_key = ‘wdm_auction_expired_by’ AND s3.meta_value = ‘ua_best_offers’
) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC;