SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9afc2be873ff03a2e0687b9379b0d45eaec2dfd8e86d6af3f96f7418c3c6ede1' 
  AND token = 'ZeP/mnRniFjYRD2mlGrc8ZC0fXyXw6/1o5dt0/TZtDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}