SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a99f484255e11388b3721ed48001cfe57710c68ab3dc3baa435003fa4ad441cf' 
  AND token = 'wKIhlWiXoB61ShDBLpdyBJJAPjDyj46MhMq4OUNGtvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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