SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '944ff7c9df523293b7141636bfc1e3eccc7224f58c178ea234d0144feb496cfd' 
  AND token = 'v45WVBvHCnigtfoKAE9x65na2FPnXt+J5sI/T3TPzpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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