SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b682d8f17386b00173fb6cb4fc14a4ad30961b35ca5ab51dd2e76c55e7b26ff' 
  AND token = 'JBtUKdPVN2SuGih4MR3iCjIj71B2YPEY3oYmzHxJpoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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