finally I found out how to catch all queries to MySQL server, generated by Acumatica. Well, in context of My SQL as usually people work more with MYOB, but under the hood MYOB is Acumatica.

Typical schema of Acumatica <-> MySQL connection looks like this:

In order to get generated MySQL queries, you may need some proxy service, which will intercept queries. You can use MySQL proxy, but instead of MySQL proxy I suggest to use Neor Profile SQL as it has much more convenient UI:

In order to achieve such catching of all My SQL queries, you'll need following steps:

1. Install Neor Profile SQL.
2. In your Acumatica web.config make following change:

  <connectionStrings>
    <remove name="ProjectX_MySql" />
    <remove name="ProjectX" />
    <add name="ProjectX" providerName="System.Data.SqlClient" connectionString="Server=localhost;Port=4040;Database=PXProjecti

pay especial attention to this part: Port=4040

3. Next goes configuration of Neor Profile SQL. Create connection to MySQL server in a way similar to what you see on screenshot:

4. You are all set. Now Acumatica will send SQL queries to Neor Profile SQL, while Neor Profile SQL will re-translate them to My SQL:

Summary

If you need to catch generated My SQL queries, you can go with My SQL query proxy and logging all files to file. Or with help of Neor Profile SQL you may get nice tool for tracking all generated queries. 

And also with such steps you can track everything that MYOB generated!