SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81300802ac5fc33d3eda5c3d1b1a659170cd2e140aff83ba566faaea9c8d2899' 
  AND token = 'ZNwJLejUZngBP2/EvhZrKcTITNrbkhYi+7l287Ujuag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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