SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46195b8a762736857f835174bbfc4cce356c8597e688d34f61bfda5e7bca67e7' 
  AND token = 'vr87AFvJdPpuUJow+wi7RIqGF/TXlnaAyZSbxKLqN+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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