SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd264934c12a9149596bf3e61b8e4932ca5993fba50461682046ea7a861308f39' 
  AND token = '2oxjpOVyscoAC/BSthAP8kFZKmSitmwZWgaR5Wv5ojw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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