SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2860892668f8372c0d2e5cf11262a4863f7ce2ba5c6212f344399f52f1f6537b' 
  AND token = 'ZNLv2jjVz/82/5h9SFDBL7c0MWGHM+PacWtyWC/zwxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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