SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8562df99ad69fac8b002157d37153aaa3cc4986c4456ffc2bb719ba764e2d89e' 
  AND token = '/Kjb083CYVlb6m5aXzsFTiZQnro1yKuHJLGjaUD6s8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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