SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19e307166afad736a7205ab284fe0773c014947ac2b2359ab0ee9cb73ed203e6' 
  AND token = 'E2lI73G5Zl/ZyKEaHBZk/wSl6//A2H7P+dtkleaxJsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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