Mindfulness does indeed slows down the current moment:

One antidote might be mindfulness, the researchers suggest. People who try to live “in the moment” may better appreciate the uniqueness of those moments once they have passed, making it less likely that they’ll be swallowed up into a “chunk”. Meditation and engaging with art may perhaps also help, they write, since “these experiences have the potential to re-sensitise us to the satisfaction of simple things and, perhaps, counteract life’s quickening pace”.