SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1803e98ac54708818652a8b747a3e3f11ab697af10b6b16e0b7edc01b169f60' 
  AND token = 'rMDhkLFmQJAIpJbcMoZu+5jgNaRNUtxfFAmdAedhqJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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