Yes and no. You probably won't get hired solely on your knowledge of Lua itself. It's possible, but because of how simple it is, you would definitely not be hired over somebody that knows a more lower level programming language on top of Lua.
Lua is powerful and used a lot. Time and Time again it demonstrates the ability to cut shipment times in have while still delivering an efficient product.
Games like Don't Starve, World of Warcraft, Garry's mod, and so many more implemented Lua not just as a scripting language, but a language to write -very impactful- game code on. The reason is because it can allow you to develop and accomplish certain tasks much quicker than say C++. However, it needs to be provided that functionality first.
So to answer your question realistically, no. You can probably find an indie studio, or a very specific position that is looking for a Lua programmer but ultimately it's best to know a lower level language because then you'll understand more about memory management, efficiency and optimization, and how Lua can be implemented. If your strictly speaking in the scope of freelance/indie, then yes it would be possible.