SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f7aec1ffa2a6de1c83ae61bbb57c345aa7ddeabdbe562f441092e0c6a72e620' 
  AND token = 'VpQQF+633Y/RlzpdOxbcMOyQM/RfWCJwDCfafVrXidI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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