heavy load on mysql server

Hi, I am having some issues from time to time. i managed to fix this issue with my cache stack, varnish/redis/memcached but it seems to come back. my hosting company send me this. I have a big server 64gb, 18 cores all dedicated just for this site

here is what they wrote. any help to pinpoint this issue?

Cloudways Tech SupportToday at 21:26
Hi,

Mysql is putting quite heavy load on the server, I am sharing you the queries which are putting this extensive load.

Every 20.0s: mysqladmin –defaults-file=/root/.my.cnf status; echo “================”; mysqladmin –defaults-file=/root/.my.cnf processlist… Tue Apr 7 01:23:35 2020

Uptime: 7856 Threads: 50 Questions: 3326399 Slow queries: 212 Opens: 344 Flush tables: 1 Open tables: 411 Queries per second avg: 423.421
================
| 47604 | gsvunyrkkt | localhost:53413 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47606 | gsvunyrkkt | localhost:53418 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47613 | gsvunyrkkt | localhost:53442 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47616 | gsvunyrkkt | localhost:53455 | gsvunyrkkt | Query | 1 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47618 | gsvunyrkkt | localhost:53461 | gsvunyrkkt | Query | 1 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47622 | gsvunyrkkt | localhost:53481 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47623 | gsvunyrkkt | localhost:53483 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47624 | gsvunyrkkt | localhost:53485 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47625 | gsvunyrkkt | localhost:53489 | gsvunyrkkt | Query | 0 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |
| 47627 | gsvunyrkkt | localhost:53493 | gsvunyrkkt | Query | 1 | Copying to tmp table | SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_postm
eta ON ( wp_posts.ID = wp_ | 0.000 |