SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99f3f7691488b8733e4f1c146acbc246c448004ab1feabb3efa29115565f053e' 
  AND token = 'JCzFVdJF8jzz7k2jjsD0JPRIChe6/qQe+YwMqQdYNgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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