SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368fd7468f13b0ab200bedcc3e755a4d79a2eb569cba530533579daa6d7e6dbb' 
  AND token = 'az7Xq/zhE+xGk2a+YNFWSwP83ofycTrTzXo546vzNOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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