SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fafa3e2993d0f67d028c67847176f21b398306eb4c3d16b62786fbd8db9e8cc' 
  AND token = 'eQhyBNioipuLa8ZPa1ENVSXQPnOnduEvlAFovi24x6Q=' 
  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"
    }
  }
}