SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baf54d14bfbe88ce33da297cca9afe2e85ca5a5f6db2ea049198a50dce3399d8' 
  AND token = 'lXOLyrxa7tRCdZ6VCRGe0cseRU8w/7rCMwmMaIBBHg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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