SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa7d6ec6a98d716ea2dbf7ea31824733873ea5b75fd61553150e649a196168a5' 
  AND token = 'O0tnKzY35+BAqaPEThGzD8V4RALhZaEbpCi6/IAKZd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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