SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d0a6a4399cf9b2994c42af1ea36f1f1e224e0f39bf6337bd05952c46959397' 
  AND token = 'K5Y+uzYs5GRElBV/Zfw0t+axcJaONp4U7w2LTjzHX2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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