SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75d0966602cb911aeae63e5b102729d5076de6b0c1becf972c312bdf20e718ee' 
  AND token = 'dwNfZITljdUbU6a0oBi2vAqlNpt+n7NFGIam8EybgEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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