SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f4522db06b1aa1f9e5ea4ca6d41d5f13b3bc1ca6d82618d978ac0f7ff1921b73' 
  AND token = 'CBRwq1pNUYdIZ80znJmGkBYpRHMwj7VaaCb98S8dv94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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