SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81ee675a0a9dbd0efb2b71a7f66c77a7405bdd4813f997f8334c9259f17b5644' 
  AND token = 'H8ZvXEZMqButJ+CZqlAGEJDAn2hZLT7iXd1QcAfPpBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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