SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c464ba755e65e08a48f2e5b29f0c545c1d9f11cd60cab68dab410be0f3b98c86' 
  AND token = 'LHQRWsPJmBWfuqesNYd/zZHpYF5cR4jLgK+vh8eeJqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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