SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '88607b951ec1c0c164298b9d61470cb0ad7b82e5fd2d825190fb2eb3a8d7dc9c' 
  AND token = '8lV/U4W03zluQeSKbyUYoiWcWtvCBKn4gftJpqBhYck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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