SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e71ac42567fcc742a1ca80d8419cc5a33086295faf0b850dc2b32fe40615e94' 
  AND token = 'Zap2XTItiGWShKlq0UECq55VCWdGub/cke5h2dOj4QQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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