SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02d3c580fc8b1d190fbb546a87ac0bcd9eb0ba55085915a126762645bb289fa2' 
  AND token = 'wDfSYi/gPQIqAR1b42M5kWSsNz8iv/YZFC3/DpMkHSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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