SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a72a4d136f7a9f8ad03e32b68f80c7ee07b80a2862255b14d8351cdad1afe886' 
  AND token = 'pQgQtlz6TfpohhR+VkO/yUSzPiKV8+qJuoDbFfzzSJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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