SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4fd539c39f7724d6cfd265388ee86ebd5bf600b5118b9e67c3d4cf0a1495274d' 
  AND token = 'BQuo6NuTFSwFADZBVcZoNx5H1P6R4WmOGm9OAOkScOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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