SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1475f429967c54d07388ec4e2b786f02fc590d7c9742b9f448c632156a6b58f6' 
  AND token = 'zmkbfWu2I/9x6sV/NBkSM39/ZgwglQMxjH1C9oNmujU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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