SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c26446f7b599abd87dd55ba42e6f975cce12d2cbaf50eb3880710c8826e3ad65' 
  AND token = 'n3sTQxDEY6HZrel8JKpIYaslc3xSg7N2DognaPbVFBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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