SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '995aeda91d005eacf629c849a36747c2fa67a27a406e12c6bc53700738a8a73c' 
  AND token = 'NbKf3Qshij+pu+oaSTHVN2/Rbw2IKQ4Hl60tvuMy76E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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