SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb06a3b8ef5d73ee2d31621962cd761f06dc95def845511648a966c93be9d35a' 
  AND token = '8ssIKSnNf16UFZGWGVFpeEkYX5WcpJEpKmDpegsM5xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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