SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2a0fbaf42aba229c3f7962cff3119886ae8c8a0474d25ea3b162ead59f91bdf' 
  AND token = '+C7Wfql84dxBhgGCkJnVKqZIDl2dTO3grQxJqyvK8TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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