SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cecb85332273b8654726a6d8954aeec081a82d27e4d04808cf8d09962061a0c' 
  AND token = 'a/Y89GeDDNsrZmywIoEPswskYpS5L1dvyD18Mj8ZDlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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