SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51f44274437a8c8b75471ed865f3561b37eb299164f521f79fc23d18c4347471' 
  AND token = 'CEB+oD4h+DGLS6KtYG1xYyflX7478Y5qnZiiJHwRjBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}