SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9af59bc20c7d49319ec9735aa78b20256b2c764c6ffb4da4fc40d8aea8112cf4' 
  AND token = 'bMnbPLam9Xw0kR7UhSaS2SXrPRuONdgVhsQNaB64D/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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