SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9d3b19a50a6953d25803e2efcbba16b8fa09088644e73ceaa42240e21fabad4' 
  AND token = 'HSKod4mZqsx1c2ompbOxvsZ+KSdvS0Ex++olqO01qa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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