SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6970ec727c55d060ccafda8978cea80d31a1960182198ec52ddf31e88a7181f' 
  AND token = 'mD2Arxp6670+Kg+N0BSQzekZoEb5y4Sslp3V0FCk+Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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