SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29922b8b8211422dcff77e2066bfff36ce8bc3b6b03313b9681f94cb7fb3724d' 
  AND token = 'J41PAYBGuos8ecLBB12oF8gXqpLN9D8ZHY703ElUuWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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