SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2dd4e213616bc4af23a48c79a4815df30a7caa28b39be00c1d3fa1175a32d67' 
  AND token = 'vOYLIiKrVqdgxYl+8fo4ZWA/WtJUhNMplgaVk4yoLFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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