SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55abc0d803ff74781a1b3f408e2b6fd603466bd616072ca1c223465f1b46ae61' 
  AND token = 'EPv0UrZD5ux3P9ZlQhH9KMXzw+W8n5ABTrg/QpyM6R8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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