SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '707de8b7eef105fda160192dbb24fd3c79207260eff2a6a2600a0892dcac3ccf' 
  AND token = '2zpolWSuK9ex9X77e6RY/JP6hxjB25bYZMo1kb/NBys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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