SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069135d7d19ecf4f6826ec8357d33915d810b822438d3db7a8cba791a5b60c51' 
  AND token = 'rqq2PzHhaxLpjBECH0c9hyBY0K8vFHtlMWVJgtBareM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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