SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '362911b8452d4b37a5ff839db6c6dc7f93dc1b2e8cbe0dcee322a9c6b824a5e0' 
  AND token = '4TSwKb5Uxw9XfTwhFl2LPm1wL3PhI7EHaaxmkNaLuOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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