SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '77b6d0a10964c817be3d8fef775a1693b0a4682141d94d77be2fb5ce1b5e644c' 
  AND token = '/uXvKpLZG9EVu4byXO7CepiqURa6UUfIYwaalkupBKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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