I was researching for the items to exchange with the tokens and thought of sharing this consolidated list with everybody.
Please let me know if something is inaccurate.
Hope this helps! :)
look for Mint in Alker Harbor. These show up with [L] prefix:
Mystic Coin from the Lunar New Year 2020 Event
look for Mint in Alker Harbor. These show up with [W] prefix:
Crystallized Snowflake from the Winter Tide 2019 Event
look for Mint in Alker Harbor. These show up with [F] prefix:
Mana Blossoms from Flora Festival 2019 Event
look for Mint in Alker Harbor. These show up with [H] prefix:
Voodoo Dolls from the Hallows Eve & Day of the Dead 2019 Event
look for Mint in Alker Harbor. These show up with [DD] prefix:
Bread of the Dead from the Hallows Eve & Day of the Dead 2019 Event
look for Mint in Alker Harbor. These show up with prefix [ S ]
Seashells from Summer Solstice 2020 Event
Or you can convert them into Event Ribbons and exchange them for the corresponding Event Ribbon Rewards. Primrose in Alker Harbor has the items.