SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c589504979b87c3073170f9e2defd5a24cd1297fdedf44516d255c49d110877a' 
  AND token = 'p3iwQVsymAVsU3PYYIDG5nOCvHtpq4Q6MIB5xUscO1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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