SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '846e8d2b36986d02fd3c3d9e8384d7418461f7ac433f39c698132d5e3d31fef8' 
  AND token = 'Rkw92i+nl2ODh7UlwdWglPMQOeMex+SrbxTjECK6f/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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