Good questions. But apparently there is such a drug, or tiny pill.
GHB or Rohypnol? how fast acting would they be?
How to Recognize GHB
GHB can be a tablet, capsule, white powder or clear liquid. It is usually mixed with a flavored drink or alcohol, which can mask its slightly salty taste. GHB is commonly hidden in water bottles, eye and nasal sprays, and mouthwash containers.
https://www.verywellmind.com/rohypnol-and-ghb-basic-facts-66989