SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd309e79cd1ee177691875c0975c97fdd18490bf98846cef5772a4dd02a3131f6' 
  AND token = 'l1+JJF/fz5uhdKvd6VcLoajWOSdOnpn7ywVqh9H2j/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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