SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e6ef9f861e8496ff161c52e36fae7c2f55cd109573bd078d7a5b5f198100bc9' 
  AND token = 'EIOt0H7ZhNyYRK9Mv5/r+zPF7e+Tj7yAObnqYpcMhqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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