SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65aecf8c68e1e97cb9be48e8cf53315ce7b0997dbcb50a70109529886f3f00b0' 
  AND token = 'Fl5/RZdfYwyEe5zQhQjgiZExNIrJOZYwPZHQSXnJOYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}