SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2a754c1c9d34b26b93b42aa7c854728da61bb4fb8f756af175bee2fb0615b68' 
  AND token = 'jaxMtP/3nNUrL06KPEx769izXPVgK+WBKKczP3ORQ/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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