SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb6fa9ce392fab7761ce59f0a0cf434cb26937ecbd722baafb34cfdd8a743655' 
  AND token = '09TfUJKTil4OwbDs+zAZBh12uq6qmTwaA1bVpOYiCyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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