SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72b128aa618082c5c7247c34174a87de5dc094d3491b68108a9972dcf31733e3' 
  AND token = 'tYDPxX8GIpRVBTIydslyGvxZMKsVHc1hVTZYV69IKDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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