Laravel: Generate random unique token

I have a table in my database called keys that has this structure:

id | user_id | token_id | token_key

Every time a user logs into my site, I need to generate a new token_id and token_key set for that user. How can I generate a random token for both the token_id and the token_key while keeping the two values unique?

For example, if:

• token_id is dfbs98641aretwsg,
• token_key is sdf389dxbf1sdz51fga65dfg74asdf

Meaning:

id | user_id | token_id         | token_key
1  | 1       | dfbs98641aretwsg | sdf389dxbf1sdz51fga65dfg74asdf

There can be no other row in the table with that combination of tokens. How can I do this?

via Chebli Mohamed