SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca4ac4d3e1f75c4a08c30fea381e06a22e458a4938f741236eccda18905e6c3' 
  AND token = 'lHqHzm5CjxYvQnPw7cb5OuithFSsGcAtc/VwKKDLXms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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