SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ed723045c0473597ca24eb0bacf418a2773299735d1d93a8eee1c4424eca8de' 
  AND token = '/AMWdCRQ7M0ILKzlzYcAqFM/I78D94fgtNNmDTATpQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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