SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dd320dcf0226d4904d7858b22d31cd04bc74181c2f7f93561a41de57608e601' 
  AND token = 'CA2+0K5uyclI5KO1ZrJMK8gZXvGKXrO4EoKZDAATCac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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