SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '829f81c0aae508b65439da121af15b81df2cd43516e3351f96ef3206fb28e9db' 
  AND token = 'bubqwgyEYOMwoFDUux7MwwTO80YoCP6QELa1SKkeoF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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