SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '039766bbf4009894f8364f26bfc07eb8be45efe1cce30cd5c270a9c6258b883d' 
  AND token = '7KoW6wfCN/YSPVHT1Lpu1oDmukG+ZkQuyoZ6RFAqMSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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