Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cdfe7de425250948827d314a814a0891844a89d4580c7852067650c4ae241711' 
  AND token = 'SragO1k55KPmv8RTBCOqJPH5IIZNbxFuqddE0fH1sBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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