SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b21b372053e428f871a3ef5440d07ada209fc25b0bb8053d3d89e9f2582612d' 
  AND token = 'v9d8yhXPxOoTm/5XD7/cTxHwOEFvzKRzCj9jsgiAco8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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