SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8663a6702f1741a1c1452d706ede995694dd3aa8cbb18f41db6377135456135d' 
  AND token = 'vWTnFSTNbHIHdKtxTw+iJqHiOCtbqtQbrgelgwqKxZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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