SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f4f79f3bf192de6cec50051aa20f56478c9942d798033885cb6c98ab82b59be' 
  AND token = 'C/KAahpxgsVzDQIgoRViLwzZMQd1pACWorNzbq8F104=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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