SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e17ca5e7d7cc66f17d1faa989149ffd59bc1112e63d58e486ebb5a92a7ccfaa' 
  AND token = 'BKPevwGecn0XUFFl7efMjWCxkHmgKhZ8Zy+SqJNt/bA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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