SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9514660228b8a7b6f5bb51d8efee404488e5835c738cd3087bd793c8943f6dca' 
  AND token = 'ZmvJY4zcw9Id66ThIdju78z45JZFZPGYv8tYX99lf+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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