SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70eb8351cb1649956e9bb78c53db4eec8a7ad38186fd9613614d84de0860905d' 
  AND token = 'cysPKtd9FSMdzSL+CeljuT0/l/0iFK9UGMfSY+FRNp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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