SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcade7386b9329c74ac9e5e3a90ace1b38781c9a03139dbc96d5aeeba097b930' 
  AND token = '3hcus+PK3JxvZ8NyI5wNv7u1ZkUxoWtnwoerk9dyQ4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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