SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af8f4f86034231b5226482411011a23a2fb6a029e67abb93d55bb841a0c70b64' 
  AND token = 'KJSsbjb6VteOHT1dsjIyMgcmERmorDp7EMNgW0vDdK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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