SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ce72c9e798d36d43c91225f9fecc14ddb28fc1fc81017ba36a5dcfcfac65022' 
  AND token = 'JslvYxwRHvO8UVSJM9wfu972Tyg16NBTPxpc3r3jf3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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