SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c07fa0096e85705ae7d6f0fd11c638c302da58a47a358fc6edee71484c34ac38' 
  AND token = 'TAvMxq4TqpJPjCYu3oDdEea1tbyftM+v+IvI6BIoUyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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