SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98ce6ecad694b8c5f612fc234607792db31b796d39b7f25efd3e42d629f39e5b' 
  AND token = 'sTIXuGPzn9E6tOPUuAcpLXmumCoPdccZmDt9bMTPoZM=' 
  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"
    }
  }
}