SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c4583ee0896f0780554532ea7405a35d1b59cfa077b43bbbd3fe1bdaa38b206' 
  AND token = 'iQKRlKqmmltlKaNqRtpDpAg7/Yrq25Pseo8TB1cfrLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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