SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a196fa7f5899d3e50635c89aab8b94706ffc67d7f614215a34159f0e64189ac3' 
  AND token = 'Yt1FV2UZ4Y1L3oDIBjph45hh+BBuRyNPpUHJnn1Fe1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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