SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98b7e1db3a522e490bbff206915c6345c858785287cfbf3fd9023ed5925e8aa3' 
  AND token = 'Z2xv1KDcMmYXMfwYIsL8gGnQw4x6Vg1/FZ01a8wWiTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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