SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9580b3ad84b2574855ad1bae0a32aba04c065a245d02665a2eafdaebb91f8424' 
  AND token = 'sWhVc8f/6d3hW+Zy1cMIPJLzm8WDnZPnOnmWixV0K6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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