SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98a8147ffb88a22f4b21e95ecf7f4efee28cfd6dd729cedba60f1fc44cd113c6' 
  AND token = 'w4e+f3CSBw1ifmO+22mLGQHbGQzfNnlYws1107eXw1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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