SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e957887d2246329729e917be94821d3de9215fc1bce5b27ced9a1998ffbd2b02' 
  AND token = 'BYPnZrfZXELaXaCN8/EiTtPXQq+8jfVKLgbEKlxEUNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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