SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59a790629962060e086aaaff55428ef1fdffd6169f85dfbbfd7fb4448b8e4ad1' 
  AND token = 'qrkEcXCmrs3XdU+IjYoWbKzSgBigkdcD4bO5uBCa1VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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