SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9b30ac517e767ad42b07a4429c060ab2584cc1ae8c57f4f26ed208a8c4938f' 
  AND token = '8ss++prehLCWoo6kSzclFkvxLqHRMyybMKxBkKylo3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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