SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84ac479093d75cb9dd545104f5be4edc6e018bb747d86bb76da1212135345d46' 
  AND token = '2GoOZidN/Q97oKvAapmCvk/vuwig6pCGHBgTGUDb0PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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