SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baa01e87ac7aaea8028db5dc7aba8bb5e5202e73a459240dfaa74bbd5fccf5c4' 
  AND token = 'zdVIwCW9amqonpqSkuWRolv5KXhYiBOrAsV1qKk5xoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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