SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d53d1776b56a23fb6dbfe9d68e3164273f2af561a2ba50c3615ef03212ab8b1' 
  AND token = 'XHHX+adoYtjXHwSVsvgsSvxrNdjlBBblf+bf0vwZIEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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