SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd1b39f1b8c880541de27af4c16e545dcaf9e351a3347576343e5ca4f50790fd' 
  AND token = 'xCENXBrwj/oEZIEQ0v8G31rosw3MXNfC8EqGlqHt5lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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