SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67c8146672308fa22b53e508b8bca7213e142c03194e8d3dc10ddfca1af72231' 
  AND token = 'J3sstyeNiDj5S5HTlr3FVtfxl1Po144mUhPsjjWtN+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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