SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'db302308b8898c95a0933cc8104f48451656be0c6385b75669c39f3b535ebeed' 
  AND token = 'NIxXr3d39mZK+nSxE3F3XYLkr6wsg1o7a3qX4/Exdvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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