Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f76c99aff250aafd7184cf3d9f68823ad20d9f3c45b36dfacfe4fb0ab7863f19' 
  AND token = '8/xrDUZgf6z/kdrroOJ5ZA0nzbiaMTkfvEPdVf5daKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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