Aliexpress plugin and wordpress help?

I bought Aliexpress plugin and installed it on my wordpress. After that I added about 20.000 products (PC hardware) from aliexpress. Now my home page took 10 seconds to load. How is this possible? I mean only 20.000 products. I have dedicate server 32GB RAM 12 Cores 1GB/s and SSD hard drive.

So I contacted support of plugin and I said "I had lyrics website with almost million rows in DB and my page loading was about 0,2 sec. Also I said why they did not add rowID to the URL so selecting of rows would be more faster." and they told me...

@@@Hello,
The data comes separately from AliExpress and it is gathered in different tables and doesn't look like one table for one product, the structure of the database and its tables is complicated and it is just impossible to do it the way you describe. Lyrics websites usually have more simple structure and don't use relational database.
Another thing about affiliate websites is that the key point is indexing. I've just checked (mywebsite.co) google search results and when I go directly to a products page from search results it takes about 2 sec to open the page. And affiliate website's main idea is to be well indexed and show a lot of pages in search engine to bring visitors and sales, so, your homepage and it's download speed is not the key.@@@@

What should I do now. I know that google will not index 20.000 pages from my website if website is too slow. Maybe it will index but my position will be 6th page...

Look into caching and cdn plugins? this way each page will only need to be downloaded once, and then after that will be super fast. You could also send a bot to your site to pre-download/cache all the pages, so theyre fast for google to munch. I think you could also go into mysql itself and put an index on that table, check stackoverflow for how to do that. Just off the top of my head tho...