SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e30462fec6cfb3134d3647413a10152fc2263456d83fc31f8e32898df9f5833' 
  AND token = 'HnEE3EseMhix+5mpJOqKCBvqs3ARChZysz6/+tvcJwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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