SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '193d724f28b5b5593f6ca4490d657cf1e1c41e6eab19311564156a817ad69f1c' 
  AND token = 'keVzqLFVszLWnxW03PsfdErAxCCN5+XyqlTqmyMlbwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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