If you never use Mission Control than it is possible to disable the feature entirely and save resources. If you disable Mission Control you also disable the Spaces feature, before disabling Mission Control, close all of your spaces.
defaults write com.apple.dock mcx-expose-disabled -bool TRUE
Restart Dock the make changes affect:
To restore Mission Control:
defaults delete com.apple.dock mcx-expose-disabled
Again restart the Dock to make changes affect.