Light travels faster than sound, which goes only ~1100 feet per second or 767 mph. The fastest your nerves transmit an impression could be 200 mph. Factor in a moment to process your sensations received and it will still require a certain distance to process the sound as a "boom," distinct from the flash which will always reach you before the boom, whether you "see" it or not. In other words, our nerves aren't reliable to judge the speed of either unless at a distance.

https://hypertextbook.com/facts/2002/DavidParizh.shtml#:~:text=%22Depending%20on%20the%20type%20of%20fiber%2C%20the%20neural,a%20breackneck%20200%20or%20more%20miles%20per%20hour.