SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6496169dddef41d91a9cf9bc192192a9a778ca4ce39e7dbd6c58d000a729b866' 
  AND token = 'YhHwI9NY5TOCSOtdQDxQVTf8llqORPKYHdngtsB/7O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}