SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d42b2e985047662d3db90375db4ab10927c863c3833f83d0d67fa81395976cc' 
  AND token = 'Xgm0VNA2ywrob/F/CC3n2xfwqpwmxW6RF9OGDKpd+DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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