SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca5b26595b05f2c08758a780d60edc35dbdf3d6316e80914e7b449e967e9a50d' 
  AND token = 'PhrnYHn5rMqoPgQd+ldP8EsORycWIQTTc7rVU6ytLdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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