SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372cc33ae49ef027e9ee42762f219c85ffe2478d42fa4f479a919b3c459eb934' 
  AND token = 'szyplHahLqaHsPOKD8T/KdNpD7L4p6Rf+mbnHsrlrwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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