SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca735b9fd0bf2260db4a14c4063fb4f7a97345a2672ed58cb1372a454956a2c5' 
  AND token = '0LE8QQmhFiAB+qofbQEhHOKErkhqDlJKEK3dtR7yHgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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