SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd823d631ff6409e55bf57ea1638adf0d031e9f77cb9580467a4833e3e4b441af' 
  AND token = 'vwJNZjijgLB2K5IuDY4VnXErB+v91XiKvDdM8WouFFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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