SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4631fbac4f1bf4577ebcdf9a6831a7a06a2b4e59c57cae18dd3dad162f1c415b' 
  AND token = 'VgKBWLQAv+RmKJfw633zBO97bUYrNN6RRzxbhSQAYw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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