SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ee1eaa24eb512c9004833781374bc78ffef245ecf09297ceb5f25961bd2e394' 
  AND token = 'EhusRdGTHpCwRpwyAAgcvQNxzKmxsraDyH8ghyCUX5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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