As mentioned, ESP-NOW is an option.
Getting Started with ESP-NOW (ESP8266 NodeMCU with Arduino IDE) | Random Nerd Tutorials
I would recommend beginning there and seeing if it's fast enough. The reasoning is that the ESP-NOW protocol is easy to use and specifically designed for these devices. Also, it does not require a router as it is direct connect.
It might not suit every project but it's where I would start.