SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9faf839f112e35bc5b7bb46c8e7e731c12dfb467ed3ce05875dd9ab9f15e77cd' 
  AND token = 'sJfKS8cTpiBQxjIopayd0bGOXq4etd2Ley9bIyaajE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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