SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f708d2c9cf56eac2addab72802df19e8920c2582b8e201a539283477f8f911a' 
  AND token = 'yqJN7iyRXzwm9lOOjs8gYRCjLTI/LJx7QMKcYqo3Q6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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