SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80cfc77529dcb9d9e867f737a0b9ebd105fd8438d6cbac8ebaac686380348e9a' 
  AND token = 'lIWmQ+oCoIcZW+975/DZdEdSdbsFOXrrtB7DiOYUbag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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