SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad34d3f93fd05b340369aff75275bdd6270256abcfe53e41995d9a1c45de171' 
  AND token = 'h2F+zH1OWurrMwIYqVG0uNKCHKOqjs58/Aq7H9Kvlg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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