SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b2015b96a6f15dd8ba708ba78ec8470754acc16b61ef2a96f1208db76b4a177' 
  AND token = 'YdqQ9Ws2WGfTjX2JiJE41hIUXU6x5Bd36VxRKgzR47A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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