SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f792e3761dce1f48041b99685aae4d8769d09b1b46bfcba14b57ca1ed666bea' 
  AND token = 'TfHbjrleFlL18ICs5G93YrkCu2rmcvWvUayIQgllbA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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