SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fa7d5b6af4fefd3f7a843b1deda19b7f85ab1131edf72fba169832dcd800425' 
  AND token = 'N1VxL4slNnlLvPFZxQAl7V5Zn12MnwXSL7yjLJ2F8qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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