SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd85b5c4bb0bfe5e4f91141df3675ad93f92498111a4527f2d9fd83b3361b2267' 
  AND token = 'b9biVeilq64sT5mIZ+d/GUYhIBG3EeNZHw3bwKV4JVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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