SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c082d5b7a63f48679761e7b1fbec5ae8d6df007ae92c98e5428390367fa131d3' 
  AND token = 'm86xJhDfwy8jBYo9BKg2y50ENkeDlgJPLhqc+mImnAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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