SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '49d5aabd5cb1a80f96e36f17208b4e28559eef92e24a4f0ad383c3252ab35094' 
  AND token = 'gbxPf9ypwS+R8vtIzvAyrZQN6APQg50EMxJAsZz0RA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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