SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63be8d6d4f2049b438f4a480b6ec8adbe9b3a155b9e33d2dec95716f76c65312' 
  AND token = 'ZHC9/YpimpMe8r6Nos8XUSRRpwpwrn5rHG9+xLPgBPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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