SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e656b05635802752d570827b5a42cf2fb7ab6c5bf65176c102eff72f3d614e4' 
  AND token = 'r+HSWaPeXlLMhpnXLhzPgarEOsjdFQOLaCg22EsU+yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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