SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '928b26a96f20d33c6475ba59b02f51eda2968f94f135bd13ab6d11c387996ab4' 
  AND token = '2vCEiczj2/mPFKhCPzYvdgvKcV4RNMoUpU5/SR9amDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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