SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b60b10be844226ae92397133a6457acab9f7ce570e992c293eaca87e0c3af9ad' 
  AND token = 'pVE7XsT4SnkW8gQBQxxrDygpZRviuVKYO0gCuic8vYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}