SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b3775ba822068aa0705b1e88583325f65ce70f9821c4473f7b9335dfeb62a8' 
  AND token = 'dgG+ZIttxx9DMlB4tvkQh0QLwTs5npD0b/xIYNJFXIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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