SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60d3fe195fc3409585257815ecb64b507b6aa7ed464d4208e532514a37a2f207' 
  AND token = 'pWAnwPYJVKC/XYtfrsznd0Xmy5NEUGcydB+Mo6cZXXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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