SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395b11547ff61cc3a95b8ccc52eb201444257b72609f069ec9a2fae3a5134a49' 
  AND token = 'UdDyqyNkv1bm8oviiSFBDaFT0eKgJrXmp7TvW45UrOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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