SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28c0a060f5d7a2e7737443ecb0e02d98f23dbc09b69ab3ba047a6bacd36bc82f' 
  AND token = 'V6nZylbSWwrIbs0yRypvsEnsjUCw/m5S9VBhf8iyDKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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