SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '334773943907d062b15c0735b9f9516f0828c77933b50351810f3e2115faa099' 
  AND token = 'VuVYc2qG69Aj8esxTOA6Tc+8KS1ZKVvhxVVq2Z/EWPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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