SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f8c67194290427f36c3173a38ee3de1a4f8ee417c94467afa8e2e279901aed72' 
  AND token = 'TtPEQ2IVH8jkOt0T4TF0CoUBgBTLL98/G557XYB49fU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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