SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3f0eba3e820c00f3335c6df739bf5d77124775a9fd4a16a55a691b35c4c31a0' 
  AND token = 'nvkxteKdp0jVK/GtGEsUdUFuRb4g2YuBDuc5sQSei28=' 
  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"
    }
  }
}