SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05516a543d68c3b28cd9d1eb7bf2d695fb57b1d5650d0a3375f9111cdbb7350d' 
  AND token = 'NPRKKCy5JhzUZztWK3BMNqxnj9aOkgYb7KVjlgwFwgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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