SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca6b8336ec7ee055e525e64a48537b64999e97b8aa8f442d394c3cd550cef9b' 
  AND token = 'iYffvnu+fDkuiFpTIHIYlZ91KPleLtWf5Esz56dFKAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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