SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c9c7e16a2aa828243cc85220820c7a9719decbc6fff688db0d5ac7dcb4e2d6a' 
  AND token = '9DEFR3PDxJqUhKkuyBVNVKpeJtvN8m+jJMHilZIgwZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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