SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '158adb628f8a6e55f551231889f78b549f2f56099423e34ebb3a0274fb52ee68' 
  AND token = 'D+kkV3IKxX7vSeKUI6GQ9EgcNx9qJhNlXMaY5zxcJUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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