SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0366b9cbb60c5bd777b295a1ea3cd89ad9677ae40a2b92d758f5f665c4958b' 
  AND token = 'wolgA7vNeVmS2sbS/SKxPMnv5109s3pqwbyTbnv8Czs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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