SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445e839f0192a9c42d0d0ff1749d6ffca398f415f0938675ce7caba000a1b808' 
  AND token = 'Tu/ClKhuj2YNaklasQj8VneM4TVQQ8qnZrMq0nvACA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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