SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c396b4c662a4f0896497548a046d48fea374312f0a3a2eed6da278855f7bec5c' 
  AND token = 'wVnjm/c7ir3KC3pCspb3yK3Dq1NJO7gJNT+4bhWFRnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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