In Bitcoin and many other cryptocurrencies, we can create and sign a transaction that will not be valid until after a certain period of time. This is often used to lock down money used in a protocol while allowing for the protocol to time out and return the money if the protocol fails.
An example is prepaying, where you regularly buy stuff at a shop and you want to reduce the number of transactions sent to the blockchain, so you create a multisig or shared account between the party and the shop. Whenever the customer wants to buy something, they simply sign a new transaction sending that amount plus the amount the customer already owes to the shop, sending the rest back to the customer. This allows you to buy any number of things with only 2 transactions posted to the blockchain. However, if the shop is malicious and refuses to serve the customer after the money is put in the shared account, then the customer needs to be able to get their money back eventually, so a time locked return transaction would be created before any money is added to make sure the money can't be locked down forever.
Note I am not talking about transaction unlock time, where a transaction is posted but can not be used as an input for a period of time. Instead, I want the transaction itself to be invalid until a certain period of time has passed.
Is there a time locked transaction mechanism in Monero?