SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f1989dc8ddf54f83be8a2098e7a64b0a2bbe429c4872a4eff46806ea86d2dbc' 
  AND token = 'Spq1XbgJMlRRbqkGSa7IKMCWwXXjpZnUQL+6D6072DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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