SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad23836ebd649edfee515b450b5a19ff5f8fe6dbf4652096f0afa1d7f1631e5' 
  AND token = 'nkXNP0bvGmrTPS9SERZzlxBhfh9yqRwFzaDU50eAsNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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