SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0108dfc0ac27741b74c730f8ba6841208d6ab066b11fdd8ef216d9a43ed69b7' 
  AND token = 'UcC8R3fYJrmxwvBGfjQeSEAguNzq2zkXRrZcOLvbCkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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