SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35202934b9d07980c53cc2fe41fa770ebfd5bc6df13d9e6ec4d008a5cc16fe2a' 
  AND token = '6B2QvIJrAGO3IZa23RqIWBJiJYH1ypZmVNcJKxhKYvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}