SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '412ad3ca693ccb82f6a458ca1769ef9f01aa7846e83ac1d645a569bc29a27ba8' 
  AND token = 'nBOugwJIvWzwgJuNvNMl4IGObFuL2r9iB8Knxw/o50w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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