SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '673b7ca221111e1f22881a393ccebe65c52ee3fddf019ee17721875402a96bce' 
  AND token = 'AO1RnLTDpwtanDYMKRd1xQD0zDAO5rTJvo5ukPfxIuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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