SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae23fa4a222f8b4937751c1dcaa05585aaa33917fea0dcb7072d0a4b35f646e2' 
  AND token = 'F9o8mJ6wNtYMp1pPZy5lW35AMmGFMeihu7bA/JKJVmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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