SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325deff3ee9a401d838f42f845b7b487c40839968c2b6269d6b6b333e12edcfa' 
  AND token = '7yAbLhyx4BYVPuZQso6sh0dvYGJXz+S5c6s5xbGf1gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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