SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6bba2d4c82bcb54abcf6a75dedc65e17295a1b9af26abdceae8a39648152591' 
  AND token = 'CCwYjA03BAHoJdil3nyMVao0q+8E4PNCQnjKzLVPJzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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