I'm using two external monitors, and I want to be able to disable the built-in monitor without closing the lid. Option with disabling brightness doesn't fit my requirements because I don't want every time to search my cursor in the black screen. I need the lid to be opened because I'm ofently using touch id sensor.
Yes, it's possible. Well, I can do it. MacBook Pro, MacOS 10.11, if that matters.
Just find the spot where the lid sensor is, (about 1/3 from the bottom on the left edge of this laptop) and park a magnet on it. The internal display goes dark, but the external still displays, and the keyboard types, and both the trackpad and external pointing devices still work.
It moves the dock onto one of the external screens, of course, and other items shift accordingly, taking a few seconds.
This is not a standalone answer, but since comments can't contain pictures, I added a new answer showing the picture requested in a comment above.
Here's a picture that shows a magnet in action, fooling the lid sensor into believing the lid is closed while the lid is open. The purple thing is a magnet used to attach a paper to a whiteboard. The paperclip on the screen shows how I found where the lid magnet was. I tried to be careful to not scratch my screen (actually the border of the screen) while moving it around to find the location.
The short answer: not possible.
Please see an earlier answer for what’s possible. There is a mode called “Closed Clamshell Mode” but no way to shut down the internal monitor while open. I suggest you simply close the machine while using external keyboard and mouse/trackpad.
This also makes sense because turning off the internal display on a laptop could lead to issues when disconnecting external ones.