SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bb88578850350de7b1181d951c56c8c292308ba31b4a75c6ae832c85f5cff80' 
  AND token = 'IUHcYQmFQhZJCXWZoYzd2tGNKkA/eJ3qoKz6j/zX7U8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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