The best move and the right time to do it! Naturally Black cannot take on e5 since there is a fork.
After this trade, we eliminate the defender of the c5-square, which will be accessible for our knight after fixing Black’s pawn structure on the queenside.
Creating a favorable structure! Now the knight will travel all the way to c5. After that, a rook can come to b3 creating tremendous pressure on the queenside.
A very interesting piece sacrifice! White sacs a piece and in return gets two protected passed pawns. Moreover, the knight on h5 and the g7-bishop are very far away from the action!