SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33c0deedf1fdc16bafdcae3a5fd65f4d0181bc976beb47c781beac017485cc8c' 
  AND token = 'NAettgoCkBRSOUjBaPnNW7NzKvGCPEdAdRGTZPWa2YI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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