SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd59db4c7da945bad203feedf1486c8067f4e4601d1e3318ef64837cad84a7a43' 
  AND token = 'lLhaclyjRQTxxvnTsLd7doRDD1Bv4itgg4XhFsba/w0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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