A guide to Korean Beauty Product Expiration dates
Unlike most beauty products that feature a printed expiration date, Korean beauty products sometimes only feature the date of manufacture. Korean beauty products typically last between 30 and 60 months (2.5 years to 5 years) unless it has an expiration date on it dictating otherwise.
Here is the Tony Moly link explaining more:
Please don't panic if the product you receive only has a date on it that is passed. That is the date it was made, not the date it expires.