Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'acb2e87b1cb5eb7818a6b3272212a4fb1a279a434af89ad89899da2bc3e6a378' 
  AND token = 'xGQEkodxAc1GzbgG+LCWkb6FZzMjrbu2NrFu46jwh8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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