SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '848cabc7f26ddf7eff341e2a4d05e791f81159d0eb8e32d0382da3fbb442e939' 
  AND token = 'C9AjqPAeKpHQak35UuE/hUo2JoXm8u6NnkmVFHcup+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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