SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bbab44ecd4227b6d1027ae40ea83d1b203a664b3cbe5e2ecad3c78524542768' 
  AND token = 'psORlozwjg5alfBvKkxpp20QB6Nrgcr7JlMkeNu1lJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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