SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3786714f2a1f1439fab3c8b9c8255e5565362000db0a35513a0e1094f026346c' 
  AND token = 'MIazfLzcSyCoFAskx31g6OY6uF8ZTcQ5HFCsHkrpLwE=' 
  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"
    }
  }
}