SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ce0ebe4dea04f6e6ae861c1e7624e095a6920a9e8b8f6ca5ea970c4285a00d' 
  AND token = '63sOUuXJrq1SfHhZJWJAkIskVtVcIUd/1Afd7qGNz9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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