SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f22dfe56b671e21847b6a8c8dc573bec1b8d0931cc504d69e465171cb38a784' 
  AND token = 'wkB+V5n5wk7dJLHvxhYB6lP5w/8JZIPMrYvGCikqu+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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