SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b97f83a06f8c23d7ad1eb20b543b8672029921a8d7440bf3481c89728638a838' 
  AND token = 'JnIzph9KAAOI5pCl8AYmBgWk/zGzSlJDry7lwcmKzdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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