SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d43f54325aa9e1cdba80aef757b170704d125c9c39dfc66c92f7d9110c87a98' 
  AND token = 'aL/ofZB25EVz3OLo+6hEGT9PZZJg8/jUgrUG0rHv1TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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