SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8ab5b5ec5a0510a25bf34d2babebfd14662d33b0b11f8f5870744da75625713' 
  AND token = 'IVvOBwviHkbUsWtXlG5Y/g6dNbOb74aGJi/V9o2mQQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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