SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6276cbcc55059b3a69ea7badd4c53b8ef6dad28542e87e02f8ea0184dd3d984' 
  AND token = 'M9NZDCuzDNGN+J5KxbG02kqYn6vsi6ItrASuEh+mYGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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