SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eb2aedfa2d641b9e393165106cf425b9ee84fc294e5af939d4208218553c922' 
  AND token = 'KXIN/Sa8qUNYqHvwKJKmdDEhzFGyNT/uAIwhk9A+Uxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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