SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f0963cf16520a9bd0c5d8410a58c461b91a43d3bdd7b5270bb03281ca0b471' 
  AND token = 'qNBHwdiIVNniyxyHWmoKesZUPU4IrLcl9E272hiL+7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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