Keys get stuck

Whenever I play, and press more than one button at once, it frequently (but not consistently) freezes with the key as if it were pressed e.g right click, WASD. This is annoying and occurs not just in vanilla minecraft, but also if I use optifine (which others have listed as a possible resolution). Please help as it is starting to render Minecraft an annoyance. Note: The issue is temporarily resolved by repressing the key or opening up my inventory. This issue is also isolated to Minecraft so my keyboard/pc is not the issue.