SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73bb78f0af837c850031f406e94fe7417ae69bf9d930db54cb8ea63e1cef02e2' 
  AND token = 'VokqlhBzqpbb6vdz8a+ivY29wmmEMfkbcJHNXhq6rYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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