SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f2cdb2730bb410f83950bd7b2c27cf35cf1c72de1493ea36bdefcecdcc67330' 
  AND token = 'bhw2IoQ0cyeOoJ2fVutqJBKDgC1KmJooGTjhDyxuQtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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