SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd75ca25670f9006490ea4219158389d8bede8ad62fa49744918352be4bf8fcd6' 
  AND token = 'o6MnzjHcu0kDXnFTPf3Gtrz75dl2ZsV9Q2bIotHabbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}