SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5db8de947288d3939edade7a055e1eec62bd216d35a12bef07bae172425e4de' 
  AND token = 'kW+Z5uHmCUV1d9T+wtypnNWZXc86Hrt/JKQXneoVIqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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