SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe82ca119028c4622b9a3ebc5f40963e319343134a861707d185fa0c2ce4cae' 
  AND token = 'YFhjIaSBB7gkgj8cQw4vxNcmZrn+kVI18HboB/qnGEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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