SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fccb84aee144397196b06c0cb73eaaa027e473b268451066f3770acae3c0a6ec' 
  AND token = 'KziaSlP5Qk7qFsBp/Hlsdlf34usfldYIvDFCrPD+RiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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