SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25876be5f1875519bf8c45ad5f94efe55fc44f837e760f36f907cc260aac2b99' 
  AND token = 'iIFuSeYNniNlUqVlEGNZnJZFJnb/BS/8bbBxcNvIkLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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