SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d463fffb26c9dd7ed2073ed2e980d4e7f33691020d516aa85e597da9763b27' 
  AND token = 'Xia5MOMGiP0PDWKC6A4OXiIygaG68s//fuXjhfJzIow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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