How fast will sodium cyanide kill a person?

Answer 1

"Once more than 100-200 mg of sodium cyanide is consumed, consciousness is lost within one minute, sometimes within 10 seconds, depending on the strength of the body's immunity and the amount of food present in the stomach. After a span of about 45 minutes, the body goes into a state of coma or deep sleep and the person may die within two hours if not treated medically."

So, effectively, 10 seconds to 1 minute. Though you'd actually live longer, you'd have no idea.