SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38cf7c64057d11f9468c4c2553fd17b908ea83758d015ab34bc06940b7ca969b' 
  AND token = 'I6ivoTEVBJlOUuRuGGpOmDXLKBxitZm8WOTZsgH1zt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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