SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5ae2d452dc2932e9949412fa38943830cf5c4e5a2809135a61cb1b0ce602727a' 
  AND token = 'k1poBu8VqTm7zxg0KBBmPJ6SEzou+WgWkxEjIhwoFwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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