SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f97778b31ab918caff8c6d8b2a607b8309997469f0c09047e874f3c851305db' 
  AND token = 'vXS6vXX3VX5fh+vwLdIYUZFnzKFz6+Iqtcswhlukl4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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