SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7591409ff7e40ecba59e3c8414292c0ed477480c5a5ea6474bd46ce85020c79b' 
  AND token = 'szYvAdzVXJTwj9mjCau2lwAxUsiJZVIUQKPt1jFOzNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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