SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcf4c94e7f2a9ded69e9e8cc23c416d2bf570e31e50fad57729d90e9401e7da8' 
  AND token = 'JJ7Snw6tQJqEe3gEwIi9UPxVh7Z1XaD27H23x9tEHrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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