SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e49babbf7b487ce02a5636a2aa6158b254cc452c8416805cb1b42e82b4f7f1b9' 
  AND token = 'iaAHbHNByWhSSImhYSFsD0qYAno+7f+i6WezAJqBatU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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