SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19f37e283b2dc5c99fb009cab8545a8d187c5af3ab7c8d3b50a1485846207b26' 
  AND token = '+D4ggUitU/0VXvcDtLZXzdrgMu1mZ/dA39rJ/g6qBzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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