SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7fb8637e12b3e3d45c8a6214ae8266702b95eb7e7ae252fa40621a9367aa221' 
  AND token = 'qRAg43JZKObdacQdHq+Qc3urwGGHQ/ywOHV7E5jpt3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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