SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a034f2ff54d563732eb669a83e5dd1ba9c07d5692fc36b688ab7159b1c91e29c' 
  AND token = 'stykIZD8hLgpDjhBQ2IgwWqzq7U2e9seOKcNw5CeEHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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