SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62dec353df6297969a377c238604516a27d48c34a97661368e1943e46feacf5a' 
  AND token = 'wX0uKEj37j+ivSj4bfrY3AKCFlU2VznZBY8FJ13pCeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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