SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bd31039f65dbee0eb6b7295813090fbbdcf467afae2983663184aed326e3ff0' 
  AND token = 'QEWm2gX/+4RwO9jUpF5j8oXdXQ/UyufamzOqPhEvyKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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