SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc1df85b9579271d482c26020ed3cc50c485809593adc84d14b1ab6d29feaff' 
  AND token = 'HYZOzwquJXLIksIYaYaAinWpomewPuhUJLEMsz99Hy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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