SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b47c94050395550e0a2732e63d592e560ce338d6bc82b837ff46b7d5de80f858' 
  AND token = 'r0oZxVZD94UmPiyniUE5fZRg6JVH8uwjXiCj44PaLCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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