SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '152b6ac6957bec56da41e7bf9132d90abba0a88da384111fcbee01015a334d90' 
  AND token = 'CJxMNVDyfv8nuo4KIlETx3CI5lX8kKR6WnH0SXMmFn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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