I do Yoga myself so please don’t think I am against this centuries old tradition.
However, I have treated many people who have complained about their back hurting after doing this pose or similar arching poses.
The cobra pose even when done correctly, as explained to me by my wife, a certified yoga instructor, can put stress onto the joints of the low back. You must be very careful when performing it.
If you are doing yoga for low back pain and are in more discomfort after doing it I would caution you to stop this exercise or any similar back arching poses and see if your back pain is reduced.
Let me know what you experience.