SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c5a4866fe32eec9f0a171fef472db3246ee99db8e411f378bc2872310d4ef62' 
  AND token = 'YiZz5PSc4DBJTzVwo0QxoioA6qA2Fgt30FKF0vun2/g=' 
  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"
    }
  }
}