SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5270b4c8b98a0bdc0a90be7a235b44058b712932b999802fab4d6460376503c8' 
  AND token = '5augQI6RcquhTPbkRPo60qRCZhA4O53kqtK4/CDOIaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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