SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '366fee2aeee400175f13e4ad3aa00d2c1f892166d17c5bd238182b9cb0c815fc' 
  AND token = 'ysvZ249A8ZEXL3gPGvP0bSZS1jmsrQ1sFTjeGJQurWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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