SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfd1fb2bdc47300bfbb426b4e2782d5ab7616f83dc8160473b33c7586d8b5139' 
  AND token = 'nmAyGvHvhMM8YeUKGDYnSdgNS6H+XEHBZUxgewQVTlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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