SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c9a4731d2bf18a5a480a8fd4e684362c019ecd01bd8b93c840c2a7094f2ef9a' 
  AND token = '+4hiCZHNQyC/EK0g5w37buCztfbLzKkRqj3sQ0B/oDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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