SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d900c328aea1aacca887ce82f5ce9edd61f00d0afbc38dd0bad9f61cc094859' 
  AND token = 'S6xhsaprVkxT0k55N8ftc3izIc+F2RvjnjprflS+Gzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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