SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8a755cf1672784cb6ad944cbff1fc1e5711022c6d84cae010f1e76c7cef8bea' 
  AND token = 'tu23vj0l05JE9NtaomkOgMpUg9j8nYvyTAvOuLs9vbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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