SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91746ffed0886e105ac15a8f79f36b12b1fe0989554bf79017f7775b8a01bbbb' 
  AND token = 'AsIgSLaP4thDcXKmJnY+t7UmvV/WqgZWsQu/BGWNfb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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