SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '211a3740c0471a2d95191456d6ebdfc65e00ae665c87b35f45cd611d02a285d2' 
  AND token = 'XiMpzGQ1nBaSCVfNFDK6v77CRLKSEYJEvpdjGq9gcew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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