There are more than 1000 cryptocurrencies. One of them must have the properties you're looking for.
You have the PoS folks, IOTA's got an interesting strategy and some other paradigms but for now its still conjecture. Decentralized distributed technologies will likely always be slower than centralized monoliths.
There is a great irony in the fact that cryptocurrencies are designed to be finite in size to ensure their value, yet the number of potential cryptocurrencies in the world is pretty much infinite.