After viewing quite a few sample images taken with the Asus Zenfone 3s Max ZC521TL, I can definitely say that the rear camera performs quite poor ins low-light conditions. You can check out some sample images here on imgur (originally from digit.in that reviewed the phone). You can see that the camera is really struggling in low-light and there is plenty of noise in the images.
The rear camera of the Zenfone 3S Max has a f/2.0 aperture lens, which if fast, but doesn't help too much because the sensor pixels are apparently very small. There is also no OIS to allow users to take advantage of slower shutter speed and shoot at lower ISO speeds. Asus has chosen to go with a 13-megapixel sensor and I believe it uses an entry-level sensor that isn't one of Sony's Exmor RS (Stacked CMOS) sensors. I believe that if it was, it would have performed better.
To be honest, I didn't even love the colors coming out from this camera. The green really looks way of the chart and unnatural in some of the photos that I've seen. I wish I could be excited about the rear camera capabilities, but I'm not. Even sample images taken in daylight don't look that good either.
If you need that low-light performance and don't want to be limited, I think you should probably look somewhere else, the Asus Zenfone 3X Max main camera is just an average camera, nothing more. There is a two-tone LED flash at the back, so it can help a bit when shooting objects that are relatively close to the camera and need to be lit up.