SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1696a75dbe57cdfaf72f48502cd81b624a119e4c1a3c488ff18f1dacc14307de' 
  AND token = 'mFb0ULsAy2nnOJCDlPKqP+ecQAf/JD6JbEzRtZ9EC8w=' 
  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"
    }
  }
}