SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3469a914264658ced50862fd0927d7090a8ebca8d7df428896a20368d76a34' 
  AND token = 'S2774djuJbVMuRHM5UA1YPOc/PII+RymcORfu4hifkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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