SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f3fb58959496f437a9372fe61710ac1f99af7880c61a2157988f0d9020fbe28' 
  AND token = 'YI2ApwxKci6lYF99vTbxKckNA4TFgiC+4UEPfCCDa6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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