SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce0dfc5dfc9fa093174df2e403fc09dbfceb27812744dbf37f2ac8d699e99668' 
  AND token = 'i5WMWMtk0OUXsJQZXwcEBUxGcUCfAw/hXKNskVvs8gI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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