SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6ed366add150574573ed81155251609be7abf3e0333868e77f2be32009fe722' 
  AND token = 'duT6rvL/qEef72lPQesutP6aVxomEZF0JP9PezemlYU=' 
  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"
    }
  }
}