SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36fbddd3001dfe017794336b74595f6c15aef6b6e0a9a45d902445150e6fd497' 
  AND token = 'UKGgOK5mJAcw4QxV90LBeP7gaI+YSs5MWHsWH+8XCXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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