SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d82e7942a765d564b24e071ca3376fa58b3993180f2fcc7438bdb9351f5e561' 
  AND token = '462peHV8PYS9hVcPuuNgwVo0Bkghi4QTLp+mjQP7Lgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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