Salesforce just introduced Code Builder as in the link: https://developer.salesforce.com/blogs/2020/06/introducing-code-builder.html
I see in the document. They are using a pro SOQL query in VS Code as an image here: 
I also want to use it. They said it is "SOQL Query Builder". But when I search for it in extension nothing found. How to use it ?
Like much of the functionality introduced at TrailheaDX '20, including Code Builder itself, SOQL Query Builder extension is not yet Generally Available.
As far as I am aware, no GA release date for the SOQL Query Builder extension has yet been formally announced. If you're interested in joining pilots of new functionality like Code Builder, contact your AE.
You can execute SOQL query right inside your VS Code now. Salesforce introduced this cool feature. It is beta mode now and evolving. I tried this one and definitely have the potential. The one which I like is that you can now execute your query right inside VS Code (No need to open another application like workbench etc.). The problem is that you cannot use where condition or any subqueries as of now, but I am quite sure, Salesforce will introduce these in coming days.
I have written a blog post regarding this new feature, which you can check out @ https://www.sudipta-deb.in/2020/11/soql-query-builder-vscode.html
Video : https://youtu.be/LG13jPWYqVw
Agreed with David, the Code Builder and its features are not yet generally available. But then if you want to use SOQL Query Editor from VS Code there is an existing extension which you might want to take a look on.
Extension Name :SOQL Editor
