SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e572476fc29b39b269c397b738a7d79fa6d672fbdd89c4ce986a25282aeeacd' 
  AND token = 'k4nqXjab/GOqyQMOqK6GBWtMZLpvE7gPPBtbp0PR0JI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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