SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a1adacda6894c15c628d877a2d16ea0fb8348db7761dd4836a8be057cbfc3561' 
  AND token = 'KtUXc31KcsFUYS3gXvg+lZhBVbMzxxR5vGRjD4prcgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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