SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c3254e931a563475ac705ec179c565e6aafca06f07cd8b9d48979f24bb0e7c' 
  AND token = 'ozA+ViW4d/9LNlTjdtcXscs6qwE+6BkPlB1WpbY8Ydw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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