SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ae3226b7b8c9ddbd5317f5300dbb461c2e9ea1093abeda8160424cc5d4aabeb' 
  AND token = 'gIQrZKxFOwukIuq9siJ+zOXw8klCWHstLE2jHcRhYII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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