SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c79bcc497035a61f9f1f457cb402e3e27acd5e70b63e754757866910167ef60' 
  AND token = 'YvNLTO7hf5d9aSpCL/nG+V4cd89Ma9wDhd/3nXG/wEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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