SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7972469c16117b8ee9e5985b8fdb8a6c08f86d1dc8ad433b96811e659f8e6326' 
  AND token = 'xXj+5oB3TqwnOrSP//A1T1s8BM7Gy40iO/hxlIUwvJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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