SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88a1420a66945e71596d6cde8992e979c47f0a5ecb02ffc8c6d5b3c92787fca5' 
  AND token = 'XxK46PB/qjgmflq9H9fvoBuVUKhuzo3vCbIhiqrs7pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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