SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec433494dbd2e233061cce4f767cbaea342f710105d5089b9999236ea0d761e7' 
  AND token = 'rZQE+ofULlyAJa7eJqLCrZkpyq4D5C1ZyutDc94Cf+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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