SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17825931bad6563331cf659b74491966be7034ab70324238654065bc3b69f9a7' 
  AND token = 'gvmwohU6BCPjvVg73yhz+kINt6LyQjoh6L57Qrj7TNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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