SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a20934e4d9f5dde3a60db3801d539313df95ae213b678e234521a8a4b9cdeefd' 
  AND token = 'lveD5Bq04ZUrek7cHfFufzZ+H/kBYJyR6ZXUnKlGIH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}