SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd168b4912902d6b8e4a29c913085e0fc17d9483cdf89dc0c1c4cad751730c5cc' 
  AND token = '4qb6+nPy/CZAmjfXk8eaSKG0E9UoPJ+kgMeYxFFW3R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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