SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b685e1deffea05f06699434f1c7ae3db7a798eff8bfc604f80349adea8c7de' 
  AND token = 'v7+j/aT4mE6ug5tyQJFx0lMkmifhgsBZG/PtzUFM8hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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