SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00ffe60c7c991d9fb7e8704e1330b41fab248255ebd16c768405a60175a9dcb9' 
  AND token = 'g2DUG1NKTYRf7LJhQ9fSmWr3B+XtWqYtHPtghjDiZzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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