SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '410ab0e9962ce36dd212a70bf746ef8a535b8e7282159d8e61266dcf365d442f' 
  AND token = 'sHBXTJ4n6gCIfrnyhCnlWc5Q1Ca2fLqPxYfDVIFyGz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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