SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7844c7df7ce73b88acbfd3e46aafbf1ccaa9ed922b454c404966eacd28724b7b' 
  AND token = 'WE79afNC5RyLSbOc7h16t/ur5O6uuV1bfLu/lx7eFNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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