SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5ed02088b72d25b5ae527fd3f3746e372aaf2ea49e8d96ab91dc906c838b6d' 
  AND token = '8/2dcww60RZkvBATc13l4QGWz3LTdSJHgaEHqdMJFpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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