SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dde4cd96c3329f04387b1b16ca260adc2da27d7209197792c57856c20b4a48f' 
  AND token = 'TOXOdx/3S9IvEQXJOA1zeQD2Oybj6kNYbWa5JlAMI3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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