To get the chronos key you must combine the chronos chain and winder key.
Starting the trolley:
The oil additive needed to start the trolley is located in a locked store
room inside the sales office. To unlock it, pick up the flashy remote on a
desk to turn on a TV. You will see a commercial about some product from
Umbrella Corp. Make note of what the product is. Here are some that you
might come accross: Safsprin, Adravil, Aquacure. Go to the nearby computer
where Carlos just shot his zombied friend. You will be prompted for a
password. Type in the name of the product. The store room is now unlocked.