If your code is taking too long to run, you will need to either reduce the complexity of your chosen RNN architecture or switch to running your code on a GPU. If you'd like to use a GPU, you have two options:
If you have access to a GPU, you should follow the Keras instructions for running Keras on GPU.
Instead of a local GPU, you could use Amazon Web Services to launch an EC2 GPU instance. (This costs money.)
Required libraries are listed in requirements.txt