SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cb2034483bb0ec1a2f7c03faf1c98ceb7dced4dcf8b953b41aa9f53160b89c0' 
  AND token = 'FfamnfoOO7+UZU5gbxLlHHLv1zhuiinyRgKQWDQfqKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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