SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66394bd77ab10c4995dc2cdc31f1d586d7d932ba41616e9d4617daca54a7fdb3' 
  AND token = 'CcuPef3D9jbPG0QhFPedXGKunXAPlalC9Rcwk7RsAQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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