SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40ed00bface30a835abef87999cce30b42964eff9fc4d89a9751794dce2181ed' 
  AND token = 'YwpFIoSgqzuNNCCSIZDbjQYQgKMpXKP4YuQs2JTNRU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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