SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '999232e1c98ff9e1c25fa79c257312670309ffd1bce2f34d0ebbc537aecf84ad' 
  AND token = 'j5ZF0HJtaVqydWrWPnPMuHVtjAANL7Nong/8HCIOnYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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