SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bef5f8ca10f5428afb45245dc88ccc816a279e57c9f5ac765c40ccc4d3a262f' 
  AND token = '9INDz7TfJPbZ1NXzVSX3lJnlsUVuF9T+KdZ03dPFBdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00166

JSON explain

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