SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4fa49ac2e7e46793a62bc571c169477bfb5871b7faf6772e6b8f203a00cb8dbd' 
  AND token = 'z66unAWHDkpAxKIC1XkpMXRs2zgmxph+YEBqijtAOuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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