SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac57e7fed9e9463a82e547bbe01ab6670709406fd2c34978b4889d3f5159f82' 
  AND token = 'a68+MJddJ36DhPVRjr7ufEdY4zlgChTmHMKE7qUO8zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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